2026-09-03T15:16:03 · difficulty: medium · AMC 8 / AJHSME · 📨 all-at-once (1 call/model) · all sessions →
| # | Model | Correct | Accuracy | Avg/Q | Total time | Cost | $/M out | Out tok | ~Impl tok | Errors |
|---|---|---|---|---|---|---|---|---|---|---|
| 🥇 | openrouter:meta/muse-spark-1.3 |
10/10 | 100% | 4.2s | 42.3s | 1.85¢ | $4.25 | 4040 | 4365 | 0 |
| 🥈 | openrouter:google/gemini-3.8-flash |
10/10 | 100% | 5.9s | 59.4s | 2.33¢ | $3.75 | 5980 | 6219 | 0 |
| 🥉 | openrouter:~z-ai/glm-latest |
10/10 | 100% | 2.3s | 22.8s | 1.64¢ | $2.57 | 3380 | 6371 | 0 |
| 4 | openrouter:qwen/qwen3.8-27b |
10/10 | 100% | 15.3s | 152.8s | 1.54¢ | $3.00 | 5850 | 5150 | 0 |
| 5 | openrouter:anthropic/claude-opus-5 |
10/10 | 100% | 2.4s | 23.8s | 6.14¢ | $25.00 | 2150 | 2458 | 0 |
| 6 | openrouter:openai/gpt-5.6-terra-pro |
10/10 | 100% | 3.4s | 33.7s | 10.78¢ | $12.00 | 7210 | 8982 | 0 |
| Model ↓ / Q → | Q1 ans D | Q2 ans C | Q3 ans A | Q4 ans A | Q5 ans B | Q6 ans B | Q7 ans C | Q8 ans A | Q9 ans B | Q10 ans D |
|---|---|---|---|---|---|---|---|---|---|---|
openrouter:meta/muse-spark-1.3 |
D ✓ | C ✓ | A ✓ | A ✓ | B ✓ | B ✓ | C ✓ | A ✓ | B ✓ | D ✓ |
openrouter:google/gemini-3.8-flash |
D ✓ | C ✓ | A ✓ | A ✓ | B ✓ | B ✓ | C ✓ | A ✓ | B ✓ | D ✓ |
openrouter:~z-ai/glm-latest |
D ✓ | C ✓ | A ✓ | A ✓ | B ✓ | B ✓ | C ✓ | A ✓ | B ✓ | D ✓ |
openrouter:qwen/qwen3.8-27b |
D ✓ | C ✓ | A ✓ | A ✓ | B ✓ | B ✓ | C ✓ | A ✓ | B ✓ | D ✓ |
openrouter:anthropic/claude-opus-5 |
D ✓ | C ✓ | A ✓ | A ✓ | B ✓ | B ✓ | C ✓ | A ✓ | B ✓ | D ✓ |
openrouter:openai/gpt-5.6-terra-pro |
D ✓ | C ✓ | A ✓ | A ✓ | B ✓ | B ✓ | C ✓ | A ✓ | B ✓ | D ✓ |
| solved (models ✓) | 6/6 | 6/6 | 6/6 | 6/6 | 6/6 | 6/6 | 6/6 | 6/6 | 6/6 | 6/6 |
A dress originally priced at 80 dollars was put on sale for 25% off. If 10% tax was added to the sale price, then the total selling price (in dollars) of the dress was
| Model | Pick | ✓/✗ | Reasoning |
|---|---|---|---|
openrouter:meta/muse-spark-1.3 |
D | ✓ | showProblem 1: We are asked for the final price after a discount and then tax. Original price is 80 dollars. 25% off means pay 100% - 25% = 75% of original. Sale price = 0.75 × 80 = 60 dollars. Tempting mistake: subtract 25 dollars to get 55. No, 25% means percent, not dollars. Then 10% tax is added to the sale price, not the original price. Tax = 10% of 60 = 6 dollars. Total = 60 + 6 = 66 dollars. Equivalently 1.10 × 60 = 66. Check: A 45 is far too low. B 52 would be 35% off total. C 54 would be adding tax incorrectly. E 68 would be adding 10% of 80. ANSWER 1: D Problem 2: We need total time = time on coastal road + time on highway. Given time on coastal road = 30 minutes for 10 miles. Let coastal speed = v. Then v = 10 miles / 30 min. Highway speed is three times as fast: 3v. Highway distance is 50 miles. Time = distance / speed, so: Highway time = 50 / (3v). From coastal: 10 / v = 30, so 1/v = 3 min per mile. Thus highway time = 50 / 3 × (1/v) = 50/3 × 3 = 50 minutes. Total = 30 + 50 = 80 minutes. Alternative check: Highway is 5 times distance but 3 times speed, so takes 5/3 as long as coastal: 30 × 5/3 = 50. ANSWER 2: C Problem 3: We are told w,x,y,z are whole numbers, so 0,1,2,... And 2^w · 3^x · 5^y · 7^z = 588. Find 2w + 3x + 5y + 7z. Factor 588 into primes. 588 = 58.8 × 10, but do integer: 588 = 2 × 294 = 2 × 2 × 147 = 4 × 147. 147 = 3 × 49 = 3 × 7 × 7. So 588 = 2^2 × 3^1 × 5^0 × 7^2. By uniqueness of prime factorization, exponents must match: w = 2, x = 1, y = 0, z = 2. Note y=0 is allowed because whole numbers include 0, and 5^0 = 1. Now compute linear expression: 2w + 3x + 5y + 7z = 2×2 + 3×1 + 5×0 + 7×2 = 4 + 3 + 0 + 14 = 21. ANSWER 3: A Problem 4: Order the five finishers by time behind Pedro. Let Pedro's time be P. Nico finished 11 minutes behind Pedro: N = P+11. Olympia finished 3 minutes behind Pedro: O = P+3. Olympia finished 2 minutes ahead of Melina: So Melina is 2 minutes behind Olympia: M = O+2 = P+5. Olympia finished 6 minutes ahead of Luke: So Luke is 6 minutes behind Olympia: L = O+6 = P+9. Order by increasing time: Pedro at P+0 — 1st Olympia at P+3 — 2nd Melina at P+5 — 3rd Luke at P+9 — 4th Nico at P+11 — 5th So fourth is Luke. ANSWER 4: A Problem 5: Total elapsed time from boarding morning bus to arriving home. From 7:30 a.m. to 4:00 p.m. = 8.5 hours = 8×60 + 30 = 510 minutes. Time at school: 6 classes × 50 min = 300 min. Lunch 30 min. Additional 2 hours = 120 min. Total school = 300 + 30 + 120 = 450 min. Bus time (morning + afternoon) = total elapsed - school time = 510 - 450 = 60 minutes. Tempting error: miscount 7:30 to 4:00 as 8 hours. ANSWER 5: B Problem 6: Let g = number of girls. Then number of boys b = g+2. Each boy gets b beans, so boys total = b × b = b^2. Each girl gets g beans, so girls total = g × g = g^2. Beans used = 400 - 6 left = 394. So b^2 + g^2 = 394. Substitute: (g+2)^2 + g^2 = 394 g^2 + 4g + 4 + g^2 = 394 2g^2 + 4g - 390 = 0 Divide 2: g^2 + 2g - 195 = 0. Factor 195 = 13 × 15, differing by 2: (g+15)(g-13)=0. Positive solution g = 13. Then b = 15. Total students = 13+15 = 28. Check: 15^2+13^2 =225+169=394 correct. ANSWER 6: B Problem 7: The car travels 30,000 miles. At any moment exactly 4 tires are on the road carrying it. Total tire-miles delivered = 4 tires × 30,000 miles = 120,000 tire-miles. This wear is shared equally among 5 tires by rotation. Per tire = 120,000 / 5 = 24,000 miles. Tempting wrong: 30,000/5 = 6,000 ignores that 4 tires are used at once. 30,000 would mean no rotation. ANSWER 7: C Problem 8: List two-digit multiples of 7: 14,21,28,35,42,49,56,63,70,77,84,91,98. Compute digit sums: 1+4=5, 2+1=3, 2+8=10, 3+5=8, 4+2=6, 4+9=13, 5+6=11, 6+3=9, 7+0=7, 7+7=14, 8+4=12, 9+1=10, 9+8=17. Only two have sum 10: 28 and 91. Their sum = 28+91 = 119. ANSWER 8: A Problem 9: Volume of cylinder = π r^2 h, where r = diameter/2. Alex: diameter 6, so r=3. height 12. V_A = π × 3^2 × 12 = π × 9 × 12 = 108π. Felicia: diameter 12, so r=6. height 6. V_F = π × 6^2 × 6 = π × 36 × 6 = 216π. Ratio V_A : V_F = 108π : 216π = 108:216 = 1:2. Note volume scales with square of radius, so doubling diameter quadruples base area, outweighing halving height. ANSWER 9: B Problem 10: We need N > 2 with N ≡ 2 mod 3, mod 4, mod 5, mod 6. So N-2 is divisible by each of 3,4,5,6. N-2 must be a common multiple of 3,4,5,6. LCM(3,4,5,6): 4=2^2, 6=2×3, so LCM = 2^2 × 3 × 5 = 60. Positive multiples: 60,120,... N=2 gives N-2=0 which works but is excluded by >2. Next smallest is N-2 = 60, so N = 62. 62 is between 61 and 65. Check: 62 ÷ 3 =20 rem 2, ÷4=15 rem 2, etc. ANSWER 10: D |
openrouter:google/gemini-3.8-flash |
D | ✓ | showProblem 1:
**Restatement and Setup:**
We are given an item with an original price of $\$80$. It is discounted by $25\%$, and then a $10\%$ sales tax is applied to this discounted sale price. We need to find the final total selling price.
**Step-by-step computation:**
1. Calculate the discount:
$$\text{Discount} = 25\% \text{ of } \$80 = 0.25 \times 80 = \$20$$
2. Calculate the sale price:
$$\text{Sale Price} = \$80 - \$20 = \$60$$
*(Alternatively, the sale price is $75\%$ of $\$80$: $0.75 \times 80 = \$60$.)*
3. Calculate the tax on the sale price:
$$\text{Tax} = 10\% \text{ of } \$60 = 0.10 \times 60 = \$6$$
4. Calculate the total price:
$$\text{Total Price} = \$60 + \$6 = \$66$$
**Ruling out wrong choices:**
- Choice A ($\$45$) results from incorrectly subtracting both $25\%$ and $10\%$ from the original price, or similar errors.
- Choice B ($\$52$) and Choice C ($\$54$) are too low.
- Choice E ($\$68$) might occur if the tax were incorrectly computed on the original $\$80$ price ($80 \times 0.10 = \$8$) and added to $\$60$.
ANSWER 1: D
---
Problem 2:
**Restatement and Setup:**
Anh drives on two segments:
- Coastal access road: distance $d_c = 10$ miles, time $t_c = 30$ minutes.
- Highway: distance $d_h = 50$ miles.
He drives three times as fast on the highway as on the coastal access road ($v_h = 3 v_c$). We need to find the total time in minutes for the entire trip.
**Step-by-step computation:**
1. Find the speed on the coastal road:
Anh drives $10$ miles in $30$ minutes ($0.5$ hours).
$$v_c = \frac{10\text{ miles}}{0.5\text{ hours}} = 20\text{ mph}$$
2. Find the speed on the highway:
$$v_h = 3 \times v_c = 3 \times 20\text{ mph} = 60\text{ mph} = 1\text{ mile per minute}$$
3. Find the time spent on the highway:
$$t_h = \frac{50\text{ miles}}{1\text{ mile per minute}} = 50\text{ minutes}$$
4. Find the total trip time:
$$\text{Total time} = t_c + t_h = 30\text{ minutes} + 50\text{ minutes} = 80\text{ minutes}$$
**Ruling out wrong choices:**
- Choice A ($50$) is just the time on the highway.
- Choices B ($70$), D ($90$), and E ($100$) arise from miscalculating the highway speed ratio or mixing up minutes and hours.
ANSWER 2: C
---
Problem 3:
**Restatement and Setup:**
Given whole numbers (non-negative integers) $w, x, y, z$ such that:
$$2^w \cdot 3^x \cdot 5^y \cdot 7^z = 588$$
We need to find the value of $2w + 3x + 5y + 7z$.
**Step-by-step computation:**
1. Find the prime factorization of $588$:
$$588 = 2 \times 294 = 2 \times 2 \times 147 = 4 \times 3 \times 49 = 2^2 \times 3^1 \times 7^2$$
2. Matching the prime factors with $2^w \cdot 3^x \cdot 5^y \cdot 7^z$:
- $w = 2$
- $x = 1$
- $y = 0$ (since $5$ is not a factor of $588$)
- $z = 2$
3. Compute the required expression $2w + 3x + 5y + 7z$:
$$2(2) + 3(1) + 5(0) + 7(2) = 4 + 3 + 0 + 14 = 21$$
**Ruling out wrong choices:**
- If one mistakenly sets $y=1$, the sum would be $21 + 5 = 26$ (close to 25 or 27).
- Choices B, C, D, and E do not match the evaluated sum of $21$.
ANSWER 3: A
---
Problem 4:
**Restatement and Setup:**
Five runners (Luke, Melina, Nico, Olympia, Pedro) finished a race. We are given relative finish times:
- Nico finished $11$ minutes behind Pedro.
- Olympia finished $3$ minutes behind Pedro.
- Olympia finished $2$ minutes ahead of Melina.
- Olympia finished $6$ minutes ahead of Luke.
We need to determine who finished in fourth place.
**Step-by-step computation:**
Let Pedro's finish time be $t=0$ minutes (the earliest/winner).
- Pedro finishes at $0$ minutes.
- Olympia finished $3$ minutes behind Pedro $\implies$ Olympia finishes at $0 + 3 = 3$ minutes.
- Olympia finished $2$ minutes ahead of Melina $\implies$ Melina finishes $2$ minutes after Olympia $\implies 3 + 2 = 5$ minutes.
- Olympia finished $6$ minutes ahead of Luke $\implies$ Luke finishes $6$ minutes after Olympia $\implies 3 + 6 = 9$ minutes.
- Nico finished $11$ minutes behind Pedro $\implies$ Nico finishes at $0 + 11 = 11$ minutes.
Listing the runners in order of finish:
1. Pedro ($0$ min)
2. Olympia ($3$ min)
3. Melina ($5$ min)
4. Luke ($9$ min)
5. Nico ($11$ min)
Thus, Luke finished fourth.
**Ruling out wrong choices:**
- Pedro was 1st, Olympia was 2nd, Melina was 3rd, and Nico was 5th (last).
ANSWER 4: A
---
Problem 5:
**Restatement and Setup:**
Walter boards the bus at 7:30 a.m. and arrives home from the bus at 4:00 p.m.
During the day, he spends time on the bus (both ways) and at school.
School activities consist of:
- $6$ classes of $50$ minutes each
- $30$ minutes for lunch
- $2$ hours of additional time
We need to find the total time Walter spent on the bus.
**Step-by-step computation:**
1. Calculate total elapsed time between leaving home and returning:
- From 7:30 a.m. to 12:00 p.m. is $4$ hours and $30$ minutes ($4.5$ hours).
- From 12:00 p.m. to 4:00 p.m. is $4$ hours.
- Total elapsed time = $8$ hours and $30$ minutes $= 8 \times 60 + 30 = 510$ minutes.
2. Calculate total time spent on school activities:
- Classes: $6 \times 50\text{ minutes} = 300\text{ minutes}$
- Lunch: $30\text{ minutes}$
- Additional time: $2\text{ hours} = 120\text{ minutes}$
- Total school time $= 300 + 30 + 120 = 450\text{ minutes}$.
3. Calculate time spent on the bus:
$$\text{Bus time} = \text{Total time} - \text{School time} = 510 - 450 = 60\text{ minutes}$$
**Ruling out wrong choices:**
- 30 minutes assumes only a one-way trip or forgets additional school time.
- 75, 90, 120 minutes result from miscounting the elapsed time or forgetting the 30-minute lunch.
ANSWER 5: B
---
Problem 6:
**Restatement and Setup:**
Let $b$ be the number of boys and $g$ be the number of girls.
- Each boy receives $b$ jelly beans (total $b^2$).
- Each girl receives $g$ jelly beans (total $g^2$).
- Total jelly beans distributed: $400 - 6 = 394$.
- There are two more boys than girls: $b = g + 2$.
We need to find the total number of students in the class, which is $b + g$.
**Step-by-step com |
openrouter:~z-ai/glm-latest |
D | ✓ | show# Problem 1: **What is asked:** Find the final price after a 25% discount on $80, followed by 10% tax on the *sale price*. **Step 1 — Compute the sale price (25% off):** Discount = 25% of 80 = 0.25 × 80 = $20. Sale price = 80 − 20 = **$60**. **Step 2 — Add 10% tax to the sale price:** Tax = 10% of 60 = $6. Total = 60 + 6 = **$66**. **Rule out wrong answers:** - $52 (B) comes from wrongly taking 10% off the *original* price (60 − 8), but tax is added, not discounted. - $54 (C) comes from adding discounts: 80 × 0.75 × 0.9 — but tax increases the price. - The correct sequence is 80 → 60 → 66. ANSWER 1: D # Problem 2: **What is asked:** Find the total driving time in minutes. **Step 1 — Coastal road speed:** Anh drove 10 miles in 30 minutes (= 0.5 hour). Speed = 10 ÷ 0.5 = **20 mph**. **Step 2 — Highway speed:** He drove 3 times as fast: 3 × 20 = **60 mph**. **Step 3 — Highway time:** Time = distance ÷ speed = 50 ÷ 60 = 5/6 hour = **50 minutes**. **Step 4 — Total time:** 30 + 50 = **80 minutes**. **Rule out wrong answers:** - 90 (D) would result from wrongly assuming equal speeds (30 min + 60 min); but the highway was faster, so its time is *less* than 60 minutes. Only 80 fits. ANSWER 2: C # Problem 3: **What is asked:** Given 2^w · 3^x · 5^y · 7^z = 588, find 2w + 3x + 5y + 7z. **Step 1 — Factor 588:** 588 = 4 × 147 = 4 × 3 × 49 = 2² × 3 × 7². **Step 2 — Read off exponents:** 588 = 2² · 3¹ · 5⁰ · 7², so w = 2, x = 1, y = 0, z = 2. **Step 3 — Compute the expression:** 2w + 3x + 5y + 7z = 2(2) + 3(1) + 5(0) + 7(2) = 4 + 3 + 0 + 14 = **21**. **Rule out wrong answers:** 35 (D) or 56 (E) would come from confusing the coefficients 2,3,5,7 with the bases; note 588 is not divisible by 5, forcing y = 0. ANSWER 3: A # Problem 4: **What is asked:** Determine which runner finished fourth (in order of finishing time). **Step 1 — Set Pedro's time as P (a reference).** Then: - Nico finished 11 minutes behind Pedro: Nico = P + 11. - Olympia finished 3 minutes behind Pedro: Olympia = P + 3. - Olympia finished 2 minutes ahead of Melina, so Melina = P + 3 + 2 = P + 5. - Olympia finished 6 minutes ahead of Luke, so Luke = P + 3 + 6 = P + 9. **Step 2 — Order from fastest to slowest:** Pedro (P), Olympia (P+3), Melina (P+5), Luke (P+9), Nico (P+11). **Step 3 — Fourth place** is **Luke**. **Rule out wrong answers:** Nico (C) is last (5th), Pedro (E) is first; a common error is swapping Luke and Melina — but Luke = P+9 is behind Melina = P+5. ANSWER 4: A # Problem 5: **What is asked:** Total time Walter spent on the bus (both ways). **Step 1 — Total elapsed time from 7:30 a.m. to 4:00 p.m.:** That is 8 hours 30 minutes = 510 minutes. **Step 2 — Time accounted for at school:** - Classes: 6 × 50 = 300 minutes - Lunch: 30 minutes - Additional time: 2 hours = 120 minutes - Total school time: 300 + 30 + 120 = 450 minutes. **Step 3 — Bus time:** 510 − 450 = **60 minutes**. **Rule out wrong answers:** 90 (D) would ignore lunch or additional time; 30 (A) would count only one bus ride — but the round trip must be 60 minutes total. ANSWER 5: B # Problem 6: **What is asked:** Find the total number of students. **Step 1 — Set up equations.** Let g = number of girls, b = number of boys. Each boy gets b beans (b boys), each girl gets g beans (g girls): b² + g² = 400 − 6 = 394, and b = g + 2. **Step 2 — Substitute and solve:** (g+2)² + g² = 394 g² + 4g + 4 + g² = 394 2g² + 4g − 390 = 0 g² + 2g − 195 = 0 (g + 15)(g − 13) = 0 → g = 13 (reject −15). **Step 3 — Find the total:** Boys: b = 13 + 2 = 15. Total students = 15 + 13 = **28**. **Check:** 15² + 13² = 225 + 169 = 394 = 400 − 6. ✓ ANSWER 6: B # Problem 7: **What is asked:** Miles each of the 5 tires was used over 30,000 miles. **Step 1 — Total tire-miles used:** At any moment the car uses 4 tires. Over 30,000 miles, total tire-miles = 4 × 30,000 = 120,000. **Step 2 — Split equally among 5 tires:** 120,000 ÷ 5 = **24,000 miles** each. **Rule out wrong answers:** 30,000 (D) is wrong because no single tire can be used the whole time when 5 tires share the work; 6,000 (A) and 7,500 (B) wrongly divide by the wrong quantity (e.g., 30,000 ÷ 5 or ÷ 4). ANSWER 7: C # Problem 8: **What is asked:** Sum of the two two-digit multiples of 7 whose digits sum to 10. **Step 1 — List two-digit multiples of 7 and digit sums:** 14 (5), 21 (3), **28 (10)** ✓, 35 (8), 42 (6), 49 (13), 56 (11), 63 (9), 70 (7), 77 (14), 84 (12), **91 (10)** ✓, 98 (17). **Step 2 — Identify the two qualifying numbers:** 28 and 91. **Step 3 — Sum:** 28 + 91 = **119**. **Rule out wrong answers:** 126 (B) is 63 + 63 — impossible since numbers are distinct; 140 (D) might come from 28 + 112 (but 112 is three digits). ANSWER 8: A # Problem 9: **What is asked:** Ratio of Alex's can volume to Felicia's can volume. **Step 1 — Volume formula:** V = πr²h. **Step 2 — Alex's can:** diameter 6 → radius 3; height 12. V_A = π(3)²(12) = 108π. **Step 3 — Felicia's can:** diameter 12 → radius 6; height 6. V_F = π(6)²(6) = 216π. **Step 4 — Ratio:** V_A : V_F = 108π : 216π = **1 : 2**. **Rule out wrong answers:** 1:1 (C) is the tempting "swapped dimensions" intuition, but volume depends on the *square* of the radius, so doubling the radius quadruples that factor while halving the height only halves — net effect is Felicia's can is twice as big. ANSWER 9: B # Problem 10: **What is asked:** Find the smallest number > 2 that leaves remainder 2 when divided by 3, 4, 5, and 6, and identify the interval containing it. **Step 1 — Interpret the condition:** N − 2 must be divisible by 3, 4, 5, and 6, i.e., N − 2 is a multiple of LCM(3, 4, 5, 6). **Step 2 — Compute the LCM:** LCM(3,4,5,6) = 60 (since 60 is divisible by 3, 4, 5, and 6). **Step 3 — Candidates:** N = 60k + 2 for whole numbers k: N = 2, 62, 122, ... The smallest *greater than 2* is **62**. **Step 4 — Locate 62:** It lies between **61 and 65**. **Rule out wrong answers:** 42 + 2 = 44 is a common error (using 42, the LCM of only |
openrouter:qwen/qwen3.8-27b |
D | ✓ | showProblem 1:
The dress is originally priced at \$80. A 25% discount means the sale price is
\[
80(1-0.25)=80(0.75)=60.
\]
Then 10% tax is added to the sale price:
\[
60(1+0.10)=60(1.10)=66.
\]
So the total selling price is \$66.
ANSWER 1: D
Problem 2:
Anh drove 10 miles on the coastal road in 30 minutes, so his coastal-road speed was
\[
\frac{10\text{ miles}}{30\text{ minutes}}.
\]
He drove three times as fast on the highway. Therefore, for the same distance, the highway time would be one-third as long.
For 50 miles on the highway, if he had driven at coastal-road speed, it would take
\[
30 \times \frac{50}{10}=150
\]
minutes. But because he drove three times as fast on the highway, the actual highway time is
\[
\frac{150}{3}=50
\]
minutes.
The coastal road took 30 minutes, so the total trip time was
\[
30+50=80
\]
minutes.
ANSWER 2: C
Problem 3:
The equation should be read as
\[
2^w \cdot 3^x \cdot 5^y \cdot 7^z = 588.
\]
Factor 588:
\[
588=2\cdot 294=2^2\cdot 147=2^2\cdot 3\cdot 49=2^2\cdot 3^1\cdot 7^2.
\]
There is no factor of 5, so \(y=0\). Comparing prime exponents gives
\[
w=2,\qquad x=1,\qquad y=0,\qquad z=2.
\]
Now compute
\[
2w+3x+5y+7z=2(2)+3(1)+5(0)+7(2).
\]
\[
=4+3+0+14=21.
\]
ANSWER 3: A
Problem 4:
Let Pedro’s finishing time be \(P\). In a race, a smaller time means finishing earlier.
- Nico finished 11 minutes behind Pedro, so Nico’s time is
\[
P+11.
\]
- Olympia finished 3 minutes behind Pedro, so Olympia’s time is
\[
P+3.
\]
- Olympia finished 2 minutes ahead of Melina, so Melina’s time is
\[
(P+3)+2=P+5.
\]
- Olympia finished 6 minutes ahead of Luke, so Luke’s time is
\[
(P+3)+6=P+9.
\]
Now order the runners from first to last by increasing time:
\[
P,\quad P+3,\quad P+5,\quad P+9,\quad P+11.
\]
That is:
1. Pedro
2. Olympia
3. Melina
4. Luke
5. Nico
So the fourth runner was Luke.
ANSWER 4: A
Problem 5:
From 7:30 a.m. to 4:00 p.m. is 8 hours and 30 minutes:
\[
8(60)+30=480+30=510
\]
minutes.
Walter’s time in school not spent on the bus is:
- 6 classes of 50 minutes each:
\[
6(50)=300
\]
minutes;
- lunch: 30 minutes;
- additional time: 2 hours = 120 minutes.
Total non-bus time:
\[
300+30+120=450
\]
minutes.
So his total bus time was
\[
510-450=60
\]
minutes.
ANSWER 5: B
Problem 6:
Let the number of girls be \(g\). Since there were two more boys than girls, the number of boys is
\[
g+2.
\]
Mrs. Awesome gave each boy as many jelly beans as there were boys, so the boys received
\[
(g+2)^2
\]
jelly beans total. Each girl received as many as there were girls, so the girls received
\[
g^2
\]
jelly beans total.
She had 400 jelly beans and 6 left, so she gave away
\[
400-6=394.
\]
Thus,
\[
(g+2)^2+g^2=394.
\]
Expand:
\[
g^2+4g+4+g^2=394
\]
\[
2g^2+4g+4=394
\]
\[
2g^2+4g-390=0
\]
Divide by 2:
\[
g^2+2g-195=0.
\]
Factor:
\[
(g+15)(g-13)=0.
\]
Since \(g\) must be positive,
\[
g=13.
\]
Then the number of boys is
\[
13+2=15.
\]
The total number of students is
\[
13+15=28.
\]
ANSWER 6: B
Problem 7:
During the first 30,000 miles, the car was always using 4 tires at once. Therefore, the total “tire-miles” used is
\[
4 \times 30{,}000=120{,}000.
\]
There are 5 tires total, and they were all used the same number of miles. So each tire was used for
\[
\frac{120{,}000}{5}=24{,}000
\]
miles.
ANSWER 7: C
Problem 8:
We need two-digit multiples of 7 whose digits sum to 10.
The two-digit multiples of 7 are:
\[
14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84, 91, 98.
\]
Check digit sums:
\[
14: 1+4=5
\]
\[
21: 2+1=3
\]
\[
28: 2+8=10
\]
\[
35: 3+5=8
\]
\[
42: 4+2=6
\]
\[
49: 4+9=13
\]
\[
56: 5+6=11
\]
\[
63: 6+3=9
\]
\[
70: 7+0=7
\]
\[
77: 7+7=14
\]
\[
84: 8+4=12
\]
\[
91: 9+1=10
\]
\[
98: 9+8=17
\]
The only two are 28 and 91. Their sum is
\[
28+91=119.
\]
ANSWER 8: A
Problem 9:
The volume of a cylinder is
\[
V=\pi r^2h.
\]
Alex’s cans have diameter 6 cm, so radius 3 cm, and height 12 cm:
\[
V_A=\pi(3^2)(12)=\pi(9)(12)=108\pi.
\]
Felicia’s cans have diameter 12 cm, so radius 6 cm, and height 6 cm:
\[
V_F=\pi(6^2)(6)=\pi(36)(6)=216\pi.
\]
The ratio of Alex’s can volume to Felicia’s can volume is
\[
108\pi:216\pi=108:216=1:2.
\]
ANSWER 9: B
Problem 10:
Let the number be \(N\). It leaves a remainder of 2 when divided by 3, 4, 5, and 6, so
\[
N-2
\]
is divisible by 3, 4, 5, and 6. Therefore, \(N-2\) must be a multiple of the least common multiple of 3, 4, 5, and 6.
Find the LCM:
\[
\operatorname{lcm}(3,4,5,6)=60.
\]
So
\[
N-2=60k
\]
for some positive integer \(k\), because we need \(N>2\).
The smallest possible value is when \(k=1\):
\[
N-2=60
\]
\[
N=62.
\]
This lies between 61 and 65.
ANSWER 10: D |
openrouter:anthropic/claude-opus-5 |
D | ✓ | showProblem 1: Sale price: 25% off means you pay 75%: 80 × 0.75 = 60 dollars. Add 10% tax: 60 × 1.10 = 66 dollars. (Choice C, 54, would come from subtracting 10%; choice D is correct. Note taking 25% off then adding 10% doesn't return to 80.) ANSWER 1: D Problem 2: Coastal road: 10 miles in 30 minutes, so 3 minutes per mile. Highway speed is 3 times as fast, so 1 minute per mile. Highway time: 50 miles × 1 minute/mile = 50 minutes. Total: 50 + 30 = 80 minutes. (Choice A forgets the coastal 30 minutes; choice D would come from using 3 min/mile on the highway incorrectly.) ANSWER 2: C Problem 3: The equation is 2^w · 3^x · 5^y · 7^z = 588. Factor 588 = 4 · 147 = 2² · 3 · 7². So w = 2, x = 1, y = 0, z = 2. Then 2w + 3x + 5y + 7z = 2(2) + 3(1) + 5(0) + 7(2) = 4 + 3 + 0 + 14 = 21. ANSWER 3: A Problem 4: Let Pedro's time be 0 (he's a reference). - Nico = +11 - Olympia = +3 (3 min behind Pedro) - Melina = Olympia + 2 = +5 - Luke = Olympia + 6 = +9 Order from first: Pedro (0), Olympia (3), Melina (5), Luke (9), Nico (11). Fourth place is Luke. ANSWER 4: A Problem 5: Total time away: 7:30 a.m. to 4:00 p.m. = 8 hours 30 minutes = 510 minutes. Time at school: classes 6 × 50 = 300, lunch 30, extra 2 hours = 120; total 450 minutes. Bus time = 510 − 450 = 60 minutes (both trips combined). ANSWER 5: B Problem 6: Let g = number of girls, b = g + 2 boys. Jelly beans used: b² + g² = 400 − 6 = 394. (g + 2)² + g² = 394 → 2g² + 4g + 4 = 394 → g² + 2g − 195 = 0 → (g + 15)(g − 13) = 0 → g = 13. So girls = 13, boys = 15; check 169 + 225 = 394 ✓. Total students = 28. ANSWER 6: B Problem 7: Four tires are on the road at any time, so total tire-miles = 4 × 30,000 = 120,000. Shared equally among 5 tires: 120,000 ÷ 5 = 24,000 miles each. (30,000 would be if no rotation; 6,000 is the rest time per tire, not use.) ANSWER 7: C Problem 8: Two-digit multiples of 7: 14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84, 91, 98. Digit sums: 5, 3, 10, 8, 6, 13, 11, 9, 7, 14, 12, 10, 17. Digit sum 10 occurs for 28 and 91. Sum: 28 + 91 = 119. ANSWER 8: A Problem 9: Alex: diameter 6 → radius 3, height 12: V = π(3²)(12) = 108π. Felicia: diameter 12 → radius 6, height 6: V = π(6²)(6) = 216π. Ratio = 108π : 216π = 1 : 2. (Doubling the radius quadruples volume, while halving height only halves it, so Felicia's is twice as big — not equal.) ANSWER 9: B Problem 10: A number leaving remainder 2 when divided by 3, 4, 5, and 6 must be 2 more than a common multiple of 3, 4, 5, 6. LCM(3, 4, 5, 6) = 60, so the smallest such number greater than 2 is 60 + 2 = 62. 62 lies between 61 and 65. ANSWER 10: D |
openrouter:openai/gpt-5.6-terra-pro |
D | ✓ | showProblem 1:
The dress was originally priced at \$80.
A 25% discount means the sale price is \(75\%\) of the original price:
\[
80 \times 0.75=60
\]
Then 10% tax is added:
\[
10\% \text{ of } 60 = 6
\]
So the total price is
\[
60+6=66
\]
A common mistake is to subtract 25% and add 10% of the original \$80, but the tax is added to the reduced sale price, not the original price.
\[
\boxed{66}
\]
ANSWER 1: D
Problem 2:
Anh drove 10 miles on the coastal road in 30 minutes.
Since 30 minutes is \(\frac12\) hour, his coastal-road speed was
\[
\frac{10\text{ miles}}{\frac12\text{ hour}}=20\text{ miles per hour}
\]
He drove three times as fast on the highway:
\[
3(20)=60\text{ miles per hour}
\]
The highway trip was 50 miles, so the highway driving time was
\[
\frac{50}{60}\text{ hour}=\frac56\text{ hour}
\]
Convert \(\frac56\) hour to minutes:
\[
\frac56\cdot 60=50\text{ minutes}
\]
His total driving time was
\[
30+50=80\text{ minutes}
\]
The answer is not 50 minutes, since that is only the highway time.
\[
\boxed{80}
\]
ANSWER 2: C
Problem 3:
We are told that
\[
2^w\cdot 3^x\cdot 5^y\cdot 7^z=588
\]
Factor 588 into primes:
\[
588=2\cdot 294=2^2\cdot 147=2^2\cdot 3\cdot 49
\]
Thus,
\[
588=2^2\cdot 3^1\cdot 5^0\cdot 7^2
\]
So
\[
w=2,\qquad x=1,\qquad y=0,\qquad z=2
\]
Now calculate:
\[
2w+3x+5y+7z
\]
\[
=2(2)+3(1)+5(0)+7(2)
\]
\[
=4+3+0+14=21
\]
The factor \(5^0\) is important: since 588 has no factor of 5, \(y=0\), not 1.
\[
\boxed{21}
\]
ANSWER 3: A
Problem 4:
We compare all runners’ finishing times relative to Pedro.
- Nico finished 11 minutes behind Pedro.
- Olympia finished 3 minutes behind Pedro.
- Olympia finished 2 minutes ahead of Melina, so Melina finished 2 minutes behind Olympia.
- Olympia finished 6 minutes ahead of Luke, so Luke finished 6 minutes behind Olympia.
Let Pedro finish at time 0.
Then:
\[
\begin{array}{c|c}
\text{Runner} & \text{Minutes behind Pedro} \\
\hline
\text{Pedro} & 0\\
\text{Olympia} & 3\\
\text{Melina} & 3+2=5\\
\text{Luke} & 3+6=9\\
\text{Nico} & 11
\end{array}
\]
Therefore, the order is:
1. Pedro
2. Olympia
3. Melina
4. Luke
5. Nico
So Luke finished fourth.
\[
\boxed{\text{Luke}}
\]
ANSWER 4: A
Problem 5:
Walter is at school from 7:30 a.m. until 4:00 p.m.
That is:
\[
8\text{ hours }30\text{ minutes}=510\text{ minutes}
\]
His school-day activities take:
- 6 classes of 50 minutes each:
\[
6\cdot 50=300\text{ minutes}
\]
- Lunch:
\[
30\text{ minutes}
\]
- Additional school time:
\[
2\text{ hours}=120\text{ minutes}
\]
Total time not spent on the bus:
\[
300+30+120=450\text{ minutes}
\]
Therefore, bus time is
\[
510-450=60\text{ minutes}
\]
This includes both the ride to school and the ride home.
\[
\boxed{60}
\]
ANSWER 5: B
Problem 6:
Let the number of girls be \(g\).
There are two more boys than girls, so the number of boys is
\[
g+2
\]
Each boy receives as many jelly beans as there are boys, so the boys receive
\[
(g+2)(g+2)=(g+2)^2
\]
jelly beans altogether.
Each girl receives \(g\) jelly beans, so the girls receive
\[
g^2
\]
jelly beans altogether.
Mrs. Awesome gave away
\[
400-6=394
\]
jelly beans. Therefore,
\[
g^2+(g+2)^2=394
\]
Expand:
\[
g^2+g^2+4g+4=394
\]
\[
2g^2+4g-390=0
\]
Divide by 2:
\[
g^2+2g-195=0
\]
Factor:
\[
(g+15)(g-13)=0
\]
So
\[
g=13
\]
since a number of girls cannot be negative.
Thus boys:
\[
13+2=15
\]
Total students:
\[
13+15=28
\]
\[
\boxed{28}
\]
ANSWER 6: B
Problem 7:
During the first 30,000 miles, the car always uses 4 tires on the road.
So the total number of tire-miles used is
\[
4\cdot 30{,}000=120{,}000
\]
There are 5 tires total, and they were rotated so each tire was used equally.
Therefore, each tire was used
\[
\frac{120{,}000}{5}=24{,}000
\]
miles.
It is not 30,000 miles because only four of the five tires are being driven on at any one time.
\[
\boxed{24{,}000}
\]
ANSWER 7: C
Problem 8:
We need two-digit multiples of 7 whose digits add to 10.
The two-digit multiples of 7 are:
\[
14,21,28,35,42,49,56,63,70,77,84,91,98
\]
Check digit sums:
\[
28:\quad 2+8=10
\]
\[
91:\quad 9+1=10
\]
These are the only two.
Their sum is
\[
28+91=119
\]
\[
\boxed{119}
\]
ANSWER 8: A
Problem 9:
The volume of a cylinder is
\[
V=\pi r^2h
\]
For Alex’s can:
- Diameter \(=6\), so radius \(=3\)
- Height \(=12\)
\[
V_A=\pi(3)^2(12)=108\pi
\]
For Felicia’s can:
- Diameter \(=12\), so radius \(=6\)
- Height \(=6\)
\[
V_F=\pi(6)^2(6)=216\pi
\]
The ratio of Alex’s volume to Felicia’s volume is
\[
108\pi:216\pi
\]
Divide both parts by \(108\pi\):
\[
1:2
\]
Although Alex’s can is twice as tall, Felicia’s radius is twice as large, and radius is squared in the volume formula.
\[
\boxed{1:2}
\]
ANSWER 9: B
Problem 10:
We seek the smallest number greater than 2 that leaves remainder 2 when divided by 3, 4, 5, and 6.
If the number is \(n\), then \(n-2\) must be divisible by all of
\[
3,\ 4,\ 5,\ 6
\]
The least common multiple is
\[
\operatorname{lcm}(3,4,5,6)=60
\]
So the smallest possible value of \(n-2\) is 60:
\[
n-2=60
\]
\[
n=62
\]
The number 62 lies between 61 and 65.
Indeed:
\[
62\div 3,\ 62\div 4,\ 62\div 5,\ 62\div 6
\]
all leave remainder 2.
\[
\boxed{61\text{ and }65}
\]
ANSWER 10: D |
On a trip to the beach, Anh traveled 50 miles on the highway and 10 miles on a coastal access road. He drove three times as fast on the highway as on the coastal road. If Anh spent 30 minutes driving on the coastal road, how many minutes did his entire trip take?
| Model | Pick | ✓/✗ | Reasoning |
|---|---|---|---|
openrouter:meta/muse-spark-1.3 |
C | ✓ | showProblem 1: We are asked for the final price after a discount and then tax. Original price is 80 dollars. 25% off means pay 100% - 25% = 75% of original. Sale price = 0.75 × 80 = 60 dollars. Tempting mistake: subtract 25 dollars to get 55. No, 25% means percent, not dollars. Then 10% tax is added to the sale price, not the original price. Tax = 10% of 60 = 6 dollars. Total = 60 + 6 = 66 dollars. Equivalently 1.10 × 60 = 66. Check: A 45 is far too low. B 52 would be 35% off total. C 54 would be adding tax incorrectly. E 68 would be adding 10% of 80. ANSWER 1: D Problem 2: We need total time = time on coastal road + time on highway. Given time on coastal road = 30 minutes for 10 miles. Let coastal speed = v. Then v = 10 miles / 30 min. Highway speed is three times as fast: 3v. Highway distance is 50 miles. Time = distance / speed, so: Highway time = 50 / (3v). From coastal: 10 / v = 30, so 1/v = 3 min per mile. Thus highway time = 50 / 3 × (1/v) = 50/3 × 3 = 50 minutes. Total = 30 + 50 = 80 minutes. Alternative check: Highway is 5 times distance but 3 times speed, so takes 5/3 as long as coastal: 30 × 5/3 = 50. ANSWER 2: C Problem 3: We are told w,x,y,z are whole numbers, so 0,1,2,... And 2^w · 3^x · 5^y · 7^z = 588. Find 2w + 3x + 5y + 7z. Factor 588 into primes. 588 = 58.8 × 10, but do integer: 588 = 2 × 294 = 2 × 2 × 147 = 4 × 147. 147 = 3 × 49 = 3 × 7 × 7. So 588 = 2^2 × 3^1 × 5^0 × 7^2. By uniqueness of prime factorization, exponents must match: w = 2, x = 1, y = 0, z = 2. Note y=0 is allowed because whole numbers include 0, and 5^0 = 1. Now compute linear expression: 2w + 3x + 5y + 7z = 2×2 + 3×1 + 5×0 + 7×2 = 4 + 3 + 0 + 14 = 21. ANSWER 3: A Problem 4: Order the five finishers by time behind Pedro. Let Pedro's time be P. Nico finished 11 minutes behind Pedro: N = P+11. Olympia finished 3 minutes behind Pedro: O = P+3. Olympia finished 2 minutes ahead of Melina: So Melina is 2 minutes behind Olympia: M = O+2 = P+5. Olympia finished 6 minutes ahead of Luke: So Luke is 6 minutes behind Olympia: L = O+6 = P+9. Order by increasing time: Pedro at P+0 — 1st Olympia at P+3 — 2nd Melina at P+5 — 3rd Luke at P+9 — 4th Nico at P+11 — 5th So fourth is Luke. ANSWER 4: A Problem 5: Total elapsed time from boarding morning bus to arriving home. From 7:30 a.m. to 4:00 p.m. = 8.5 hours = 8×60 + 30 = 510 minutes. Time at school: 6 classes × 50 min = 300 min. Lunch 30 min. Additional 2 hours = 120 min. Total school = 300 + 30 + 120 = 450 min. Bus time (morning + afternoon) = total elapsed - school time = 510 - 450 = 60 minutes. Tempting error: miscount 7:30 to 4:00 as 8 hours. ANSWER 5: B Problem 6: Let g = number of girls. Then number of boys b = g+2. Each boy gets b beans, so boys total = b × b = b^2. Each girl gets g beans, so girls total = g × g = g^2. Beans used = 400 - 6 left = 394. So b^2 + g^2 = 394. Substitute: (g+2)^2 + g^2 = 394 g^2 + 4g + 4 + g^2 = 394 2g^2 + 4g - 390 = 0 Divide 2: g^2 + 2g - 195 = 0. Factor 195 = 13 × 15, differing by 2: (g+15)(g-13)=0. Positive solution g = 13. Then b = 15. Total students = 13+15 = 28. Check: 15^2+13^2 =225+169=394 correct. ANSWER 6: B Problem 7: The car travels 30,000 miles. At any moment exactly 4 tires are on the road carrying it. Total tire-miles delivered = 4 tires × 30,000 miles = 120,000 tire-miles. This wear is shared equally among 5 tires by rotation. Per tire = 120,000 / 5 = 24,000 miles. Tempting wrong: 30,000/5 = 6,000 ignores that 4 tires are used at once. 30,000 would mean no rotation. ANSWER 7: C Problem 8: List two-digit multiples of 7: 14,21,28,35,42,49,56,63,70,77,84,91,98. Compute digit sums: 1+4=5, 2+1=3, 2+8=10, 3+5=8, 4+2=6, 4+9=13, 5+6=11, 6+3=9, 7+0=7, 7+7=14, 8+4=12, 9+1=10, 9+8=17. Only two have sum 10: 28 and 91. Their sum = 28+91 = 119. ANSWER 8: A Problem 9: Volume of cylinder = π r^2 h, where r = diameter/2. Alex: diameter 6, so r=3. height 12. V_A = π × 3^2 × 12 = π × 9 × 12 = 108π. Felicia: diameter 12, so r=6. height 6. V_F = π × 6^2 × 6 = π × 36 × 6 = 216π. Ratio V_A : V_F = 108π : 216π = 108:216 = 1:2. Note volume scales with square of radius, so doubling diameter quadruples base area, outweighing halving height. ANSWER 9: B Problem 10: We need N > 2 with N ≡ 2 mod 3, mod 4, mod 5, mod 6. So N-2 is divisible by each of 3,4,5,6. N-2 must be a common multiple of 3,4,5,6. LCM(3,4,5,6): 4=2^2, 6=2×3, so LCM = 2^2 × 3 × 5 = 60. Positive multiples: 60,120,... N=2 gives N-2=0 which works but is excluded by >2. Next smallest is N-2 = 60, so N = 62. 62 is between 61 and 65. Check: 62 ÷ 3 =20 rem 2, ÷4=15 rem 2, etc. ANSWER 10: D |
openrouter:google/gemini-3.8-flash |
C | ✓ | showProblem 1:
**Restatement and Setup:**
We are given an item with an original price of $\$80$. It is discounted by $25\%$, and then a $10\%$ sales tax is applied to this discounted sale price. We need to find the final total selling price.
**Step-by-step computation:**
1. Calculate the discount:
$$\text{Discount} = 25\% \text{ of } \$80 = 0.25 \times 80 = \$20$$
2. Calculate the sale price:
$$\text{Sale Price} = \$80 - \$20 = \$60$$
*(Alternatively, the sale price is $75\%$ of $\$80$: $0.75 \times 80 = \$60$.)*
3. Calculate the tax on the sale price:
$$\text{Tax} = 10\% \text{ of } \$60 = 0.10 \times 60 = \$6$$
4. Calculate the total price:
$$\text{Total Price} = \$60 + \$6 = \$66$$
**Ruling out wrong choices:**
- Choice A ($\$45$) results from incorrectly subtracting both $25\%$ and $10\%$ from the original price, or similar errors.
- Choice B ($\$52$) and Choice C ($\$54$) are too low.
- Choice E ($\$68$) might occur if the tax were incorrectly computed on the original $\$80$ price ($80 \times 0.10 = \$8$) and added to $\$60$.
ANSWER 1: D
---
Problem 2:
**Restatement and Setup:**
Anh drives on two segments:
- Coastal access road: distance $d_c = 10$ miles, time $t_c = 30$ minutes.
- Highway: distance $d_h = 50$ miles.
He drives three times as fast on the highway as on the coastal access road ($v_h = 3 v_c$). We need to find the total time in minutes for the entire trip.
**Step-by-step computation:**
1. Find the speed on the coastal road:
Anh drives $10$ miles in $30$ minutes ($0.5$ hours).
$$v_c = \frac{10\text{ miles}}{0.5\text{ hours}} = 20\text{ mph}$$
2. Find the speed on the highway:
$$v_h = 3 \times v_c = 3 \times 20\text{ mph} = 60\text{ mph} = 1\text{ mile per minute}$$
3. Find the time spent on the highway:
$$t_h = \frac{50\text{ miles}}{1\text{ mile per minute}} = 50\text{ minutes}$$
4. Find the total trip time:
$$\text{Total time} = t_c + t_h = 30\text{ minutes} + 50\text{ minutes} = 80\text{ minutes}$$
**Ruling out wrong choices:**
- Choice A ($50$) is just the time on the highway.
- Choices B ($70$), D ($90$), and E ($100$) arise from miscalculating the highway speed ratio or mixing up minutes and hours.
ANSWER 2: C
---
Problem 3:
**Restatement and Setup:**
Given whole numbers (non-negative integers) $w, x, y, z$ such that:
$$2^w \cdot 3^x \cdot 5^y \cdot 7^z = 588$$
We need to find the value of $2w + 3x + 5y + 7z$.
**Step-by-step computation:**
1. Find the prime factorization of $588$:
$$588 = 2 \times 294 = 2 \times 2 \times 147 = 4 \times 3 \times 49 = 2^2 \times 3^1 \times 7^2$$
2. Matching the prime factors with $2^w \cdot 3^x \cdot 5^y \cdot 7^z$:
- $w = 2$
- $x = 1$
- $y = 0$ (since $5$ is not a factor of $588$)
- $z = 2$
3. Compute the required expression $2w + 3x + 5y + 7z$:
$$2(2) + 3(1) + 5(0) + 7(2) = 4 + 3 + 0 + 14 = 21$$
**Ruling out wrong choices:**
- If one mistakenly sets $y=1$, the sum would be $21 + 5 = 26$ (close to 25 or 27).
- Choices B, C, D, and E do not match the evaluated sum of $21$.
ANSWER 3: A
---
Problem 4:
**Restatement and Setup:**
Five runners (Luke, Melina, Nico, Olympia, Pedro) finished a race. We are given relative finish times:
- Nico finished $11$ minutes behind Pedro.
- Olympia finished $3$ minutes behind Pedro.
- Olympia finished $2$ minutes ahead of Melina.
- Olympia finished $6$ minutes ahead of Luke.
We need to determine who finished in fourth place.
**Step-by-step computation:**
Let Pedro's finish time be $t=0$ minutes (the earliest/winner).
- Pedro finishes at $0$ minutes.
- Olympia finished $3$ minutes behind Pedro $\implies$ Olympia finishes at $0 + 3 = 3$ minutes.
- Olympia finished $2$ minutes ahead of Melina $\implies$ Melina finishes $2$ minutes after Olympia $\implies 3 + 2 = 5$ minutes.
- Olympia finished $6$ minutes ahead of Luke $\implies$ Luke finishes $6$ minutes after Olympia $\implies 3 + 6 = 9$ minutes.
- Nico finished $11$ minutes behind Pedro $\implies$ Nico finishes at $0 + 11 = 11$ minutes.
Listing the runners in order of finish:
1. Pedro ($0$ min)
2. Olympia ($3$ min)
3. Melina ($5$ min)
4. Luke ($9$ min)
5. Nico ($11$ min)
Thus, Luke finished fourth.
**Ruling out wrong choices:**
- Pedro was 1st, Olympia was 2nd, Melina was 3rd, and Nico was 5th (last).
ANSWER 4: A
---
Problem 5:
**Restatement and Setup:**
Walter boards the bus at 7:30 a.m. and arrives home from the bus at 4:00 p.m.
During the day, he spends time on the bus (both ways) and at school.
School activities consist of:
- $6$ classes of $50$ minutes each
- $30$ minutes for lunch
- $2$ hours of additional time
We need to find the total time Walter spent on the bus.
**Step-by-step computation:**
1. Calculate total elapsed time between leaving home and returning:
- From 7:30 a.m. to 12:00 p.m. is $4$ hours and $30$ minutes ($4.5$ hours).
- From 12:00 p.m. to 4:00 p.m. is $4$ hours.
- Total elapsed time = $8$ hours and $30$ minutes $= 8 \times 60 + 30 = 510$ minutes.
2. Calculate total time spent on school activities:
- Classes: $6 \times 50\text{ minutes} = 300\text{ minutes}$
- Lunch: $30\text{ minutes}$
- Additional time: $2\text{ hours} = 120\text{ minutes}$
- Total school time $= 300 + 30 + 120 = 450\text{ minutes}$.
3. Calculate time spent on the bus:
$$\text{Bus time} = \text{Total time} - \text{School time} = 510 - 450 = 60\text{ minutes}$$
**Ruling out wrong choices:**
- 30 minutes assumes only a one-way trip or forgets additional school time.
- 75, 90, 120 minutes result from miscounting the elapsed time or forgetting the 30-minute lunch.
ANSWER 5: B
---
Problem 6:
**Restatement and Setup:**
Let $b$ be the number of boys and $g$ be the number of girls.
- Each boy receives $b$ jelly beans (total $b^2$).
- Each girl receives $g$ jelly beans (total $g^2$).
- Total jelly beans distributed: $400 - 6 = 394$.
- There are two more boys than girls: $b = g + 2$.
We need to find the total number of students in the class, which is $b + g$.
**Step-by-step com |
openrouter:~z-ai/glm-latest |
C | ✓ | show# Problem 1: **What is asked:** Find the final price after a 25% discount on $80, followed by 10% tax on the *sale price*. **Step 1 — Compute the sale price (25% off):** Discount = 25% of 80 = 0.25 × 80 = $20. Sale price = 80 − 20 = **$60**. **Step 2 — Add 10% tax to the sale price:** Tax = 10% of 60 = $6. Total = 60 + 6 = **$66**. **Rule out wrong answers:** - $52 (B) comes from wrongly taking 10% off the *original* price (60 − 8), but tax is added, not discounted. - $54 (C) comes from adding discounts: 80 × 0.75 × 0.9 — but tax increases the price. - The correct sequence is 80 → 60 → 66. ANSWER 1: D # Problem 2: **What is asked:** Find the total driving time in minutes. **Step 1 — Coastal road speed:** Anh drove 10 miles in 30 minutes (= 0.5 hour). Speed = 10 ÷ 0.5 = **20 mph**. **Step 2 — Highway speed:** He drove 3 times as fast: 3 × 20 = **60 mph**. **Step 3 — Highway time:** Time = distance ÷ speed = 50 ÷ 60 = 5/6 hour = **50 minutes**. **Step 4 — Total time:** 30 + 50 = **80 minutes**. **Rule out wrong answers:** - 90 (D) would result from wrongly assuming equal speeds (30 min + 60 min); but the highway was faster, so its time is *less* than 60 minutes. Only 80 fits. ANSWER 2: C # Problem 3: **What is asked:** Given 2^w · 3^x · 5^y · 7^z = 588, find 2w + 3x + 5y + 7z. **Step 1 — Factor 588:** 588 = 4 × 147 = 4 × 3 × 49 = 2² × 3 × 7². **Step 2 — Read off exponents:** 588 = 2² · 3¹ · 5⁰ · 7², so w = 2, x = 1, y = 0, z = 2. **Step 3 — Compute the expression:** 2w + 3x + 5y + 7z = 2(2) + 3(1) + 5(0) + 7(2) = 4 + 3 + 0 + 14 = **21**. **Rule out wrong answers:** 35 (D) or 56 (E) would come from confusing the coefficients 2,3,5,7 with the bases; note 588 is not divisible by 5, forcing y = 0. ANSWER 3: A # Problem 4: **What is asked:** Determine which runner finished fourth (in order of finishing time). **Step 1 — Set Pedro's time as P (a reference).** Then: - Nico finished 11 minutes behind Pedro: Nico = P + 11. - Olympia finished 3 minutes behind Pedro: Olympia = P + 3. - Olympia finished 2 minutes ahead of Melina, so Melina = P + 3 + 2 = P + 5. - Olympia finished 6 minutes ahead of Luke, so Luke = P + 3 + 6 = P + 9. **Step 2 — Order from fastest to slowest:** Pedro (P), Olympia (P+3), Melina (P+5), Luke (P+9), Nico (P+11). **Step 3 — Fourth place** is **Luke**. **Rule out wrong answers:** Nico (C) is last (5th), Pedro (E) is first; a common error is swapping Luke and Melina — but Luke = P+9 is behind Melina = P+5. ANSWER 4: A # Problem 5: **What is asked:** Total time Walter spent on the bus (both ways). **Step 1 — Total elapsed time from 7:30 a.m. to 4:00 p.m.:** That is 8 hours 30 minutes = 510 minutes. **Step 2 — Time accounted for at school:** - Classes: 6 × 50 = 300 minutes - Lunch: 30 minutes - Additional time: 2 hours = 120 minutes - Total school time: 300 + 30 + 120 = 450 minutes. **Step 3 — Bus time:** 510 − 450 = **60 minutes**. **Rule out wrong answers:** 90 (D) would ignore lunch or additional time; 30 (A) would count only one bus ride — but the round trip must be 60 minutes total. ANSWER 5: B # Problem 6: **What is asked:** Find the total number of students. **Step 1 — Set up equations.** Let g = number of girls, b = number of boys. Each boy gets b beans (b boys), each girl gets g beans (g girls): b² + g² = 400 − 6 = 394, and b = g + 2. **Step 2 — Substitute and solve:** (g+2)² + g² = 394 g² + 4g + 4 + g² = 394 2g² + 4g − 390 = 0 g² + 2g − 195 = 0 (g + 15)(g − 13) = 0 → g = 13 (reject −15). **Step 3 — Find the total:** Boys: b = 13 + 2 = 15. Total students = 15 + 13 = **28**. **Check:** 15² + 13² = 225 + 169 = 394 = 400 − 6. ✓ ANSWER 6: B # Problem 7: **What is asked:** Miles each of the 5 tires was used over 30,000 miles. **Step 1 — Total tire-miles used:** At any moment the car uses 4 tires. Over 30,000 miles, total tire-miles = 4 × 30,000 = 120,000. **Step 2 — Split equally among 5 tires:** 120,000 ÷ 5 = **24,000 miles** each. **Rule out wrong answers:** 30,000 (D) is wrong because no single tire can be used the whole time when 5 tires share the work; 6,000 (A) and 7,500 (B) wrongly divide by the wrong quantity (e.g., 30,000 ÷ 5 or ÷ 4). ANSWER 7: C # Problem 8: **What is asked:** Sum of the two two-digit multiples of 7 whose digits sum to 10. **Step 1 — List two-digit multiples of 7 and digit sums:** 14 (5), 21 (3), **28 (10)** ✓, 35 (8), 42 (6), 49 (13), 56 (11), 63 (9), 70 (7), 77 (14), 84 (12), **91 (10)** ✓, 98 (17). **Step 2 — Identify the two qualifying numbers:** 28 and 91. **Step 3 — Sum:** 28 + 91 = **119**. **Rule out wrong answers:** 126 (B) is 63 + 63 — impossible since numbers are distinct; 140 (D) might come from 28 + 112 (but 112 is three digits). ANSWER 8: A # Problem 9: **What is asked:** Ratio of Alex's can volume to Felicia's can volume. **Step 1 — Volume formula:** V = πr²h. **Step 2 — Alex's can:** diameter 6 → radius 3; height 12. V_A = π(3)²(12) = 108π. **Step 3 — Felicia's can:** diameter 12 → radius 6; height 6. V_F = π(6)²(6) = 216π. **Step 4 — Ratio:** V_A : V_F = 108π : 216π = **1 : 2**. **Rule out wrong answers:** 1:1 (C) is the tempting "swapped dimensions" intuition, but volume depends on the *square* of the radius, so doubling the radius quadruples that factor while halving the height only halves — net effect is Felicia's can is twice as big. ANSWER 9: B # Problem 10: **What is asked:** Find the smallest number > 2 that leaves remainder 2 when divided by 3, 4, 5, and 6, and identify the interval containing it. **Step 1 — Interpret the condition:** N − 2 must be divisible by 3, 4, 5, and 6, i.e., N − 2 is a multiple of LCM(3, 4, 5, 6). **Step 2 — Compute the LCM:** LCM(3,4,5,6) = 60 (since 60 is divisible by 3, 4, 5, and 6). **Step 3 — Candidates:** N = 60k + 2 for whole numbers k: N = 2, 62, 122, ... The smallest *greater than 2* is **62**. **Step 4 — Locate 62:** It lies between **61 and 65**. **Rule out wrong answers:** 42 + 2 = 44 is a common error (using 42, the LCM of only |
openrouter:qwen/qwen3.8-27b |
C | ✓ | showProblem 1:
The dress is originally priced at \$80. A 25% discount means the sale price is
\[
80(1-0.25)=80(0.75)=60.
\]
Then 10% tax is added to the sale price:
\[
60(1+0.10)=60(1.10)=66.
\]
So the total selling price is \$66.
ANSWER 1: D
Problem 2:
Anh drove 10 miles on the coastal road in 30 minutes, so his coastal-road speed was
\[
\frac{10\text{ miles}}{30\text{ minutes}}.
\]
He drove three times as fast on the highway. Therefore, for the same distance, the highway time would be one-third as long.
For 50 miles on the highway, if he had driven at coastal-road speed, it would take
\[
30 \times \frac{50}{10}=150
\]
minutes. But because he drove three times as fast on the highway, the actual highway time is
\[
\frac{150}{3}=50
\]
minutes.
The coastal road took 30 minutes, so the total trip time was
\[
30+50=80
\]
minutes.
ANSWER 2: C
Problem 3:
The equation should be read as
\[
2^w \cdot 3^x \cdot 5^y \cdot 7^z = 588.
\]
Factor 588:
\[
588=2\cdot 294=2^2\cdot 147=2^2\cdot 3\cdot 49=2^2\cdot 3^1\cdot 7^2.
\]
There is no factor of 5, so \(y=0\). Comparing prime exponents gives
\[
w=2,\qquad x=1,\qquad y=0,\qquad z=2.
\]
Now compute
\[
2w+3x+5y+7z=2(2)+3(1)+5(0)+7(2).
\]
\[
=4+3+0+14=21.
\]
ANSWER 3: A
Problem 4:
Let Pedro’s finishing time be \(P\). In a race, a smaller time means finishing earlier.
- Nico finished 11 minutes behind Pedro, so Nico’s time is
\[
P+11.
\]
- Olympia finished 3 minutes behind Pedro, so Olympia’s time is
\[
P+3.
\]
- Olympia finished 2 minutes ahead of Melina, so Melina’s time is
\[
(P+3)+2=P+5.
\]
- Olympia finished 6 minutes ahead of Luke, so Luke’s time is
\[
(P+3)+6=P+9.
\]
Now order the runners from first to last by increasing time:
\[
P,\quad P+3,\quad P+5,\quad P+9,\quad P+11.
\]
That is:
1. Pedro
2. Olympia
3. Melina
4. Luke
5. Nico
So the fourth runner was Luke.
ANSWER 4: A
Problem 5:
From 7:30 a.m. to 4:00 p.m. is 8 hours and 30 minutes:
\[
8(60)+30=480+30=510
\]
minutes.
Walter’s time in school not spent on the bus is:
- 6 classes of 50 minutes each:
\[
6(50)=300
\]
minutes;
- lunch: 30 minutes;
- additional time: 2 hours = 120 minutes.
Total non-bus time:
\[
300+30+120=450
\]
minutes.
So his total bus time was
\[
510-450=60
\]
minutes.
ANSWER 5: B
Problem 6:
Let the number of girls be \(g\). Since there were two more boys than girls, the number of boys is
\[
g+2.
\]
Mrs. Awesome gave each boy as many jelly beans as there were boys, so the boys received
\[
(g+2)^2
\]
jelly beans total. Each girl received as many as there were girls, so the girls received
\[
g^2
\]
jelly beans total.
She had 400 jelly beans and 6 left, so she gave away
\[
400-6=394.
\]
Thus,
\[
(g+2)^2+g^2=394.
\]
Expand:
\[
g^2+4g+4+g^2=394
\]
\[
2g^2+4g+4=394
\]
\[
2g^2+4g-390=0
\]
Divide by 2:
\[
g^2+2g-195=0.
\]
Factor:
\[
(g+15)(g-13)=0.
\]
Since \(g\) must be positive,
\[
g=13.
\]
Then the number of boys is
\[
13+2=15.
\]
The total number of students is
\[
13+15=28.
\]
ANSWER 6: B
Problem 7:
During the first 30,000 miles, the car was always using 4 tires at once. Therefore, the total “tire-miles” used is
\[
4 \times 30{,}000=120{,}000.
\]
There are 5 tires total, and they were all used the same number of miles. So each tire was used for
\[
\frac{120{,}000}{5}=24{,}000
\]
miles.
ANSWER 7: C
Problem 8:
We need two-digit multiples of 7 whose digits sum to 10.
The two-digit multiples of 7 are:
\[
14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84, 91, 98.
\]
Check digit sums:
\[
14: 1+4=5
\]
\[
21: 2+1=3
\]
\[
28: 2+8=10
\]
\[
35: 3+5=8
\]
\[
42: 4+2=6
\]
\[
49: 4+9=13
\]
\[
56: 5+6=11
\]
\[
63: 6+3=9
\]
\[
70: 7+0=7
\]
\[
77: 7+7=14
\]
\[
84: 8+4=12
\]
\[
91: 9+1=10
\]
\[
98: 9+8=17
\]
The only two are 28 and 91. Their sum is
\[
28+91=119.
\]
ANSWER 8: A
Problem 9:
The volume of a cylinder is
\[
V=\pi r^2h.
\]
Alex’s cans have diameter 6 cm, so radius 3 cm, and height 12 cm:
\[
V_A=\pi(3^2)(12)=\pi(9)(12)=108\pi.
\]
Felicia’s cans have diameter 12 cm, so radius 6 cm, and height 6 cm:
\[
V_F=\pi(6^2)(6)=\pi(36)(6)=216\pi.
\]
The ratio of Alex’s can volume to Felicia’s can volume is
\[
108\pi:216\pi=108:216=1:2.
\]
ANSWER 9: B
Problem 10:
Let the number be \(N\). It leaves a remainder of 2 when divided by 3, 4, 5, and 6, so
\[
N-2
\]
is divisible by 3, 4, 5, and 6. Therefore, \(N-2\) must be a multiple of the least common multiple of 3, 4, 5, and 6.
Find the LCM:
\[
\operatorname{lcm}(3,4,5,6)=60.
\]
So
\[
N-2=60k
\]
for some positive integer \(k\), because we need \(N>2\).
The smallest possible value is when \(k=1\):
\[
N-2=60
\]
\[
N=62.
\]
This lies between 61 and 65.
ANSWER 10: D |
openrouter:anthropic/claude-opus-5 |
C | ✓ | showProblem 1: Sale price: 25% off means you pay 75%: 80 × 0.75 = 60 dollars. Add 10% tax: 60 × 1.10 = 66 dollars. (Choice C, 54, would come from subtracting 10%; choice D is correct. Note taking 25% off then adding 10% doesn't return to 80.) ANSWER 1: D Problem 2: Coastal road: 10 miles in 30 minutes, so 3 minutes per mile. Highway speed is 3 times as fast, so 1 minute per mile. Highway time: 50 miles × 1 minute/mile = 50 minutes. Total: 50 + 30 = 80 minutes. (Choice A forgets the coastal 30 minutes; choice D would come from using 3 min/mile on the highway incorrectly.) ANSWER 2: C Problem 3: The equation is 2^w · 3^x · 5^y · 7^z = 588. Factor 588 = 4 · 147 = 2² · 3 · 7². So w = 2, x = 1, y = 0, z = 2. Then 2w + 3x + 5y + 7z = 2(2) + 3(1) + 5(0) + 7(2) = 4 + 3 + 0 + 14 = 21. ANSWER 3: A Problem 4: Let Pedro's time be 0 (he's a reference). - Nico = +11 - Olympia = +3 (3 min behind Pedro) - Melina = Olympia + 2 = +5 - Luke = Olympia + 6 = +9 Order from first: Pedro (0), Olympia (3), Melina (5), Luke (9), Nico (11). Fourth place is Luke. ANSWER 4: A Problem 5: Total time away: 7:30 a.m. to 4:00 p.m. = 8 hours 30 minutes = 510 minutes. Time at school: classes 6 × 50 = 300, lunch 30, extra 2 hours = 120; total 450 minutes. Bus time = 510 − 450 = 60 minutes (both trips combined). ANSWER 5: B Problem 6: Let g = number of girls, b = g + 2 boys. Jelly beans used: b² + g² = 400 − 6 = 394. (g + 2)² + g² = 394 → 2g² + 4g + 4 = 394 → g² + 2g − 195 = 0 → (g + 15)(g − 13) = 0 → g = 13. So girls = 13, boys = 15; check 169 + 225 = 394 ✓. Total students = 28. ANSWER 6: B Problem 7: Four tires are on the road at any time, so total tire-miles = 4 × 30,000 = 120,000. Shared equally among 5 tires: 120,000 ÷ 5 = 24,000 miles each. (30,000 would be if no rotation; 6,000 is the rest time per tire, not use.) ANSWER 7: C Problem 8: Two-digit multiples of 7: 14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84, 91, 98. Digit sums: 5, 3, 10, 8, 6, 13, 11, 9, 7, 14, 12, 10, 17. Digit sum 10 occurs for 28 and 91. Sum: 28 + 91 = 119. ANSWER 8: A Problem 9: Alex: diameter 6 → radius 3, height 12: V = π(3²)(12) = 108π. Felicia: diameter 12 → radius 6, height 6: V = π(6²)(6) = 216π. Ratio = 108π : 216π = 1 : 2. (Doubling the radius quadruples volume, while halving height only halves it, so Felicia's is twice as big — not equal.) ANSWER 9: B Problem 10: A number leaving remainder 2 when divided by 3, 4, 5, and 6 must be 2 more than a common multiple of 3, 4, 5, 6. LCM(3, 4, 5, 6) = 60, so the smallest such number greater than 2 is 60 + 2 = 62. 62 lies between 61 and 65. ANSWER 10: D |
openrouter:openai/gpt-5.6-terra-pro |
C | ✓ | showProblem 1:
The dress was originally priced at \$80.
A 25% discount means the sale price is \(75\%\) of the original price:
\[
80 \times 0.75=60
\]
Then 10% tax is added:
\[
10\% \text{ of } 60 = 6
\]
So the total price is
\[
60+6=66
\]
A common mistake is to subtract 25% and add 10% of the original \$80, but the tax is added to the reduced sale price, not the original price.
\[
\boxed{66}
\]
ANSWER 1: D
Problem 2:
Anh drove 10 miles on the coastal road in 30 minutes.
Since 30 minutes is \(\frac12\) hour, his coastal-road speed was
\[
\frac{10\text{ miles}}{\frac12\text{ hour}}=20\text{ miles per hour}
\]
He drove three times as fast on the highway:
\[
3(20)=60\text{ miles per hour}
\]
The highway trip was 50 miles, so the highway driving time was
\[
\frac{50}{60}\text{ hour}=\frac56\text{ hour}
\]
Convert \(\frac56\) hour to minutes:
\[
\frac56\cdot 60=50\text{ minutes}
\]
His total driving time was
\[
30+50=80\text{ minutes}
\]
The answer is not 50 minutes, since that is only the highway time.
\[
\boxed{80}
\]
ANSWER 2: C
Problem 3:
We are told that
\[
2^w\cdot 3^x\cdot 5^y\cdot 7^z=588
\]
Factor 588 into primes:
\[
588=2\cdot 294=2^2\cdot 147=2^2\cdot 3\cdot 49
\]
Thus,
\[
588=2^2\cdot 3^1\cdot 5^0\cdot 7^2
\]
So
\[
w=2,\qquad x=1,\qquad y=0,\qquad z=2
\]
Now calculate:
\[
2w+3x+5y+7z
\]
\[
=2(2)+3(1)+5(0)+7(2)
\]
\[
=4+3+0+14=21
\]
The factor \(5^0\) is important: since 588 has no factor of 5, \(y=0\), not 1.
\[
\boxed{21}
\]
ANSWER 3: A
Problem 4:
We compare all runners’ finishing times relative to Pedro.
- Nico finished 11 minutes behind Pedro.
- Olympia finished 3 minutes behind Pedro.
- Olympia finished 2 minutes ahead of Melina, so Melina finished 2 minutes behind Olympia.
- Olympia finished 6 minutes ahead of Luke, so Luke finished 6 minutes behind Olympia.
Let Pedro finish at time 0.
Then:
\[
\begin{array}{c|c}
\text{Runner} & \text{Minutes behind Pedro} \\
\hline
\text{Pedro} & 0\\
\text{Olympia} & 3\\
\text{Melina} & 3+2=5\\
\text{Luke} & 3+6=9\\
\text{Nico} & 11
\end{array}
\]
Therefore, the order is:
1. Pedro
2. Olympia
3. Melina
4. Luke
5. Nico
So Luke finished fourth.
\[
\boxed{\text{Luke}}
\]
ANSWER 4: A
Problem 5:
Walter is at school from 7:30 a.m. until 4:00 p.m.
That is:
\[
8\text{ hours }30\text{ minutes}=510\text{ minutes}
\]
His school-day activities take:
- 6 classes of 50 minutes each:
\[
6\cdot 50=300\text{ minutes}
\]
- Lunch:
\[
30\text{ minutes}
\]
- Additional school time:
\[
2\text{ hours}=120\text{ minutes}
\]
Total time not spent on the bus:
\[
300+30+120=450\text{ minutes}
\]
Therefore, bus time is
\[
510-450=60\text{ minutes}
\]
This includes both the ride to school and the ride home.
\[
\boxed{60}
\]
ANSWER 5: B
Problem 6:
Let the number of girls be \(g\).
There are two more boys than girls, so the number of boys is
\[
g+2
\]
Each boy receives as many jelly beans as there are boys, so the boys receive
\[
(g+2)(g+2)=(g+2)^2
\]
jelly beans altogether.
Each girl receives \(g\) jelly beans, so the girls receive
\[
g^2
\]
jelly beans altogether.
Mrs. Awesome gave away
\[
400-6=394
\]
jelly beans. Therefore,
\[
g^2+(g+2)^2=394
\]
Expand:
\[
g^2+g^2+4g+4=394
\]
\[
2g^2+4g-390=0
\]
Divide by 2:
\[
g^2+2g-195=0
\]
Factor:
\[
(g+15)(g-13)=0
\]
So
\[
g=13
\]
since a number of girls cannot be negative.
Thus boys:
\[
13+2=15
\]
Total students:
\[
13+15=28
\]
\[
\boxed{28}
\]
ANSWER 6: B
Problem 7:
During the first 30,000 miles, the car always uses 4 tires on the road.
So the total number of tire-miles used is
\[
4\cdot 30{,}000=120{,}000
\]
There are 5 tires total, and they were rotated so each tire was used equally.
Therefore, each tire was used
\[
\frac{120{,}000}{5}=24{,}000
\]
miles.
It is not 30,000 miles because only four of the five tires are being driven on at any one time.
\[
\boxed{24{,}000}
\]
ANSWER 7: C
Problem 8:
We need two-digit multiples of 7 whose digits add to 10.
The two-digit multiples of 7 are:
\[
14,21,28,35,42,49,56,63,70,77,84,91,98
\]
Check digit sums:
\[
28:\quad 2+8=10
\]
\[
91:\quad 9+1=10
\]
These are the only two.
Their sum is
\[
28+91=119
\]
\[
\boxed{119}
\]
ANSWER 8: A
Problem 9:
The volume of a cylinder is
\[
V=\pi r^2h
\]
For Alex’s can:
- Diameter \(=6\), so radius \(=3\)
- Height \(=12\)
\[
V_A=\pi(3)^2(12)=108\pi
\]
For Felicia’s can:
- Diameter \(=12\), so radius \(=6\)
- Height \(=6\)
\[
V_F=\pi(6)^2(6)=216\pi
\]
The ratio of Alex’s volume to Felicia’s volume is
\[
108\pi:216\pi
\]
Divide both parts by \(108\pi\):
\[
1:2
\]
Although Alex’s can is twice as tall, Felicia’s radius is twice as large, and radius is squared in the volume formula.
\[
\boxed{1:2}
\]
ANSWER 9: B
Problem 10:
We seek the smallest number greater than 2 that leaves remainder 2 when divided by 3, 4, 5, and 6.
If the number is \(n\), then \(n-2\) must be divisible by all of
\[
3,\ 4,\ 5,\ 6
\]
The least common multiple is
\[
\operatorname{lcm}(3,4,5,6)=60
\]
So the smallest possible value of \(n-2\) is 60:
\[
n-2=60
\]
\[
n=62
\]
The number 62 lies between 61 and 65.
Indeed:
\[
62\div 3,\ 62\div 4,\ 62\div 5,\ 62\div 6
\]
all leave remainder 2.
\[
\boxed{61\text{ and }65}
\]
ANSWER 10: D |
Let w, x, y, and z be whole numbers. If 2w · 3x · 5y · 7z = 588, then what does 2w + 3x + 5y + 7z equal?
| Model | Pick | ✓/✗ | Reasoning |
|---|---|---|---|
openrouter:meta/muse-spark-1.3 |
A | ✓ | showProblem 1: We are asked for the final price after a discount and then tax. Original price is 80 dollars. 25% off means pay 100% - 25% = 75% of original. Sale price = 0.75 × 80 = 60 dollars. Tempting mistake: subtract 25 dollars to get 55. No, 25% means percent, not dollars. Then 10% tax is added to the sale price, not the original price. Tax = 10% of 60 = 6 dollars. Total = 60 + 6 = 66 dollars. Equivalently 1.10 × 60 = 66. Check: A 45 is far too low. B 52 would be 35% off total. C 54 would be adding tax incorrectly. E 68 would be adding 10% of 80. ANSWER 1: D Problem 2: We need total time = time on coastal road + time on highway. Given time on coastal road = 30 minutes for 10 miles. Let coastal speed = v. Then v = 10 miles / 30 min. Highway speed is three times as fast: 3v. Highway distance is 50 miles. Time = distance / speed, so: Highway time = 50 / (3v). From coastal: 10 / v = 30, so 1/v = 3 min per mile. Thus highway time = 50 / 3 × (1/v) = 50/3 × 3 = 50 minutes. Total = 30 + 50 = 80 minutes. Alternative check: Highway is 5 times distance but 3 times speed, so takes 5/3 as long as coastal: 30 × 5/3 = 50. ANSWER 2: C Problem 3: We are told w,x,y,z are whole numbers, so 0,1,2,... And 2^w · 3^x · 5^y · 7^z = 588. Find 2w + 3x + 5y + 7z. Factor 588 into primes. 588 = 58.8 × 10, but do integer: 588 = 2 × 294 = 2 × 2 × 147 = 4 × 147. 147 = 3 × 49 = 3 × 7 × 7. So 588 = 2^2 × 3^1 × 5^0 × 7^2. By uniqueness of prime factorization, exponents must match: w = 2, x = 1, y = 0, z = 2. Note y=0 is allowed because whole numbers include 0, and 5^0 = 1. Now compute linear expression: 2w + 3x + 5y + 7z = 2×2 + 3×1 + 5×0 + 7×2 = 4 + 3 + 0 + 14 = 21. ANSWER 3: A Problem 4: Order the five finishers by time behind Pedro. Let Pedro's time be P. Nico finished 11 minutes behind Pedro: N = P+11. Olympia finished 3 minutes behind Pedro: O = P+3. Olympia finished 2 minutes ahead of Melina: So Melina is 2 minutes behind Olympia: M = O+2 = P+5. Olympia finished 6 minutes ahead of Luke: So Luke is 6 minutes behind Olympia: L = O+6 = P+9. Order by increasing time: Pedro at P+0 — 1st Olympia at P+3 — 2nd Melina at P+5 — 3rd Luke at P+9 — 4th Nico at P+11 — 5th So fourth is Luke. ANSWER 4: A Problem 5: Total elapsed time from boarding morning bus to arriving home. From 7:30 a.m. to 4:00 p.m. = 8.5 hours = 8×60 + 30 = 510 minutes. Time at school: 6 classes × 50 min = 300 min. Lunch 30 min. Additional 2 hours = 120 min. Total school = 300 + 30 + 120 = 450 min. Bus time (morning + afternoon) = total elapsed - school time = 510 - 450 = 60 minutes. Tempting error: miscount 7:30 to 4:00 as 8 hours. ANSWER 5: B Problem 6: Let g = number of girls. Then number of boys b = g+2. Each boy gets b beans, so boys total = b × b = b^2. Each girl gets g beans, so girls total = g × g = g^2. Beans used = 400 - 6 left = 394. So b^2 + g^2 = 394. Substitute: (g+2)^2 + g^2 = 394 g^2 + 4g + 4 + g^2 = 394 2g^2 + 4g - 390 = 0 Divide 2: g^2 + 2g - 195 = 0. Factor 195 = 13 × 15, differing by 2: (g+15)(g-13)=0. Positive solution g = 13. Then b = 15. Total students = 13+15 = 28. Check: 15^2+13^2 =225+169=394 correct. ANSWER 6: B Problem 7: The car travels 30,000 miles. At any moment exactly 4 tires are on the road carrying it. Total tire-miles delivered = 4 tires × 30,000 miles = 120,000 tire-miles. This wear is shared equally among 5 tires by rotation. Per tire = 120,000 / 5 = 24,000 miles. Tempting wrong: 30,000/5 = 6,000 ignores that 4 tires are used at once. 30,000 would mean no rotation. ANSWER 7: C Problem 8: List two-digit multiples of 7: 14,21,28,35,42,49,56,63,70,77,84,91,98. Compute digit sums: 1+4=5, 2+1=3, 2+8=10, 3+5=8, 4+2=6, 4+9=13, 5+6=11, 6+3=9, 7+0=7, 7+7=14, 8+4=12, 9+1=10, 9+8=17. Only two have sum 10: 28 and 91. Their sum = 28+91 = 119. ANSWER 8: A Problem 9: Volume of cylinder = π r^2 h, where r = diameter/2. Alex: diameter 6, so r=3. height 12. V_A = π × 3^2 × 12 = π × 9 × 12 = 108π. Felicia: diameter 12, so r=6. height 6. V_F = π × 6^2 × 6 = π × 36 × 6 = 216π. Ratio V_A : V_F = 108π : 216π = 108:216 = 1:2. Note volume scales with square of radius, so doubling diameter quadruples base area, outweighing halving height. ANSWER 9: B Problem 10: We need N > 2 with N ≡ 2 mod 3, mod 4, mod 5, mod 6. So N-2 is divisible by each of 3,4,5,6. N-2 must be a common multiple of 3,4,5,6. LCM(3,4,5,6): 4=2^2, 6=2×3, so LCM = 2^2 × 3 × 5 = 60. Positive multiples: 60,120,... N=2 gives N-2=0 which works but is excluded by >2. Next smallest is N-2 = 60, so N = 62. 62 is between 61 and 65. Check: 62 ÷ 3 =20 rem 2, ÷4=15 rem 2, etc. ANSWER 10: D |
openrouter:google/gemini-3.8-flash |
A | ✓ | showProblem 1:
**Restatement and Setup:**
We are given an item with an original price of $\$80$. It is discounted by $25\%$, and then a $10\%$ sales tax is applied to this discounted sale price. We need to find the final total selling price.
**Step-by-step computation:**
1. Calculate the discount:
$$\text{Discount} = 25\% \text{ of } \$80 = 0.25 \times 80 = \$20$$
2. Calculate the sale price:
$$\text{Sale Price} = \$80 - \$20 = \$60$$
*(Alternatively, the sale price is $75\%$ of $\$80$: $0.75 \times 80 = \$60$.)*
3. Calculate the tax on the sale price:
$$\text{Tax} = 10\% \text{ of } \$60 = 0.10 \times 60 = \$6$$
4. Calculate the total price:
$$\text{Total Price} = \$60 + \$6 = \$66$$
**Ruling out wrong choices:**
- Choice A ($\$45$) results from incorrectly subtracting both $25\%$ and $10\%$ from the original price, or similar errors.
- Choice B ($\$52$) and Choice C ($\$54$) are too low.
- Choice E ($\$68$) might occur if the tax were incorrectly computed on the original $\$80$ price ($80 \times 0.10 = \$8$) and added to $\$60$.
ANSWER 1: D
---
Problem 2:
**Restatement and Setup:**
Anh drives on two segments:
- Coastal access road: distance $d_c = 10$ miles, time $t_c = 30$ minutes.
- Highway: distance $d_h = 50$ miles.
He drives three times as fast on the highway as on the coastal access road ($v_h = 3 v_c$). We need to find the total time in minutes for the entire trip.
**Step-by-step computation:**
1. Find the speed on the coastal road:
Anh drives $10$ miles in $30$ minutes ($0.5$ hours).
$$v_c = \frac{10\text{ miles}}{0.5\text{ hours}} = 20\text{ mph}$$
2. Find the speed on the highway:
$$v_h = 3 \times v_c = 3 \times 20\text{ mph} = 60\text{ mph} = 1\text{ mile per minute}$$
3. Find the time spent on the highway:
$$t_h = \frac{50\text{ miles}}{1\text{ mile per minute}} = 50\text{ minutes}$$
4. Find the total trip time:
$$\text{Total time} = t_c + t_h = 30\text{ minutes} + 50\text{ minutes} = 80\text{ minutes}$$
**Ruling out wrong choices:**
- Choice A ($50$) is just the time on the highway.
- Choices B ($70$), D ($90$), and E ($100$) arise from miscalculating the highway speed ratio or mixing up minutes and hours.
ANSWER 2: C
---
Problem 3:
**Restatement and Setup:**
Given whole numbers (non-negative integers) $w, x, y, z$ such that:
$$2^w \cdot 3^x \cdot 5^y \cdot 7^z = 588$$
We need to find the value of $2w + 3x + 5y + 7z$.
**Step-by-step computation:**
1. Find the prime factorization of $588$:
$$588 = 2 \times 294 = 2 \times 2 \times 147 = 4 \times 3 \times 49 = 2^2 \times 3^1 \times 7^2$$
2. Matching the prime factors with $2^w \cdot 3^x \cdot 5^y \cdot 7^z$:
- $w = 2$
- $x = 1$
- $y = 0$ (since $5$ is not a factor of $588$)
- $z = 2$
3. Compute the required expression $2w + 3x + 5y + 7z$:
$$2(2) + 3(1) + 5(0) + 7(2) = 4 + 3 + 0 + 14 = 21$$
**Ruling out wrong choices:**
- If one mistakenly sets $y=1$, the sum would be $21 + 5 = 26$ (close to 25 or 27).
- Choices B, C, D, and E do not match the evaluated sum of $21$.
ANSWER 3: A
---
Problem 4:
**Restatement and Setup:**
Five runners (Luke, Melina, Nico, Olympia, Pedro) finished a race. We are given relative finish times:
- Nico finished $11$ minutes behind Pedro.
- Olympia finished $3$ minutes behind Pedro.
- Olympia finished $2$ minutes ahead of Melina.
- Olympia finished $6$ minutes ahead of Luke.
We need to determine who finished in fourth place.
**Step-by-step computation:**
Let Pedro's finish time be $t=0$ minutes (the earliest/winner).
- Pedro finishes at $0$ minutes.
- Olympia finished $3$ minutes behind Pedro $\implies$ Olympia finishes at $0 + 3 = 3$ minutes.
- Olympia finished $2$ minutes ahead of Melina $\implies$ Melina finishes $2$ minutes after Olympia $\implies 3 + 2 = 5$ minutes.
- Olympia finished $6$ minutes ahead of Luke $\implies$ Luke finishes $6$ minutes after Olympia $\implies 3 + 6 = 9$ minutes.
- Nico finished $11$ minutes behind Pedro $\implies$ Nico finishes at $0 + 11 = 11$ minutes.
Listing the runners in order of finish:
1. Pedro ($0$ min)
2. Olympia ($3$ min)
3. Melina ($5$ min)
4. Luke ($9$ min)
5. Nico ($11$ min)
Thus, Luke finished fourth.
**Ruling out wrong choices:**
- Pedro was 1st, Olympia was 2nd, Melina was 3rd, and Nico was 5th (last).
ANSWER 4: A
---
Problem 5:
**Restatement and Setup:**
Walter boards the bus at 7:30 a.m. and arrives home from the bus at 4:00 p.m.
During the day, he spends time on the bus (both ways) and at school.
School activities consist of:
- $6$ classes of $50$ minutes each
- $30$ minutes for lunch
- $2$ hours of additional time
We need to find the total time Walter spent on the bus.
**Step-by-step computation:**
1. Calculate total elapsed time between leaving home and returning:
- From 7:30 a.m. to 12:00 p.m. is $4$ hours and $30$ minutes ($4.5$ hours).
- From 12:00 p.m. to 4:00 p.m. is $4$ hours.
- Total elapsed time = $8$ hours and $30$ minutes $= 8 \times 60 + 30 = 510$ minutes.
2. Calculate total time spent on school activities:
- Classes: $6 \times 50\text{ minutes} = 300\text{ minutes}$
- Lunch: $30\text{ minutes}$
- Additional time: $2\text{ hours} = 120\text{ minutes}$
- Total school time $= 300 + 30 + 120 = 450\text{ minutes}$.
3. Calculate time spent on the bus:
$$\text{Bus time} = \text{Total time} - \text{School time} = 510 - 450 = 60\text{ minutes}$$
**Ruling out wrong choices:**
- 30 minutes assumes only a one-way trip or forgets additional school time.
- 75, 90, 120 minutes result from miscounting the elapsed time or forgetting the 30-minute lunch.
ANSWER 5: B
---
Problem 6:
**Restatement and Setup:**
Let $b$ be the number of boys and $g$ be the number of girls.
- Each boy receives $b$ jelly beans (total $b^2$).
- Each girl receives $g$ jelly beans (total $g^2$).
- Total jelly beans distributed: $400 - 6 = 394$.
- There are two more boys than girls: $b = g + 2$.
We need to find the total number of students in the class, which is $b + g$.
**Step-by-step com |
openrouter:~z-ai/glm-latest |
A | ✓ | show# Problem 1: **What is asked:** Find the final price after a 25% discount on $80, followed by 10% tax on the *sale price*. **Step 1 — Compute the sale price (25% off):** Discount = 25% of 80 = 0.25 × 80 = $20. Sale price = 80 − 20 = **$60**. **Step 2 — Add 10% tax to the sale price:** Tax = 10% of 60 = $6. Total = 60 + 6 = **$66**. **Rule out wrong answers:** - $52 (B) comes from wrongly taking 10% off the *original* price (60 − 8), but tax is added, not discounted. - $54 (C) comes from adding discounts: 80 × 0.75 × 0.9 — but tax increases the price. - The correct sequence is 80 → 60 → 66. ANSWER 1: D # Problem 2: **What is asked:** Find the total driving time in minutes. **Step 1 — Coastal road speed:** Anh drove 10 miles in 30 minutes (= 0.5 hour). Speed = 10 ÷ 0.5 = **20 mph**. **Step 2 — Highway speed:** He drove 3 times as fast: 3 × 20 = **60 mph**. **Step 3 — Highway time:** Time = distance ÷ speed = 50 ÷ 60 = 5/6 hour = **50 minutes**. **Step 4 — Total time:** 30 + 50 = **80 minutes**. **Rule out wrong answers:** - 90 (D) would result from wrongly assuming equal speeds (30 min + 60 min); but the highway was faster, so its time is *less* than 60 minutes. Only 80 fits. ANSWER 2: C # Problem 3: **What is asked:** Given 2^w · 3^x · 5^y · 7^z = 588, find 2w + 3x + 5y + 7z. **Step 1 — Factor 588:** 588 = 4 × 147 = 4 × 3 × 49 = 2² × 3 × 7². **Step 2 — Read off exponents:** 588 = 2² · 3¹ · 5⁰ · 7², so w = 2, x = 1, y = 0, z = 2. **Step 3 — Compute the expression:** 2w + 3x + 5y + 7z = 2(2) + 3(1) + 5(0) + 7(2) = 4 + 3 + 0 + 14 = **21**. **Rule out wrong answers:** 35 (D) or 56 (E) would come from confusing the coefficients 2,3,5,7 with the bases; note 588 is not divisible by 5, forcing y = 0. ANSWER 3: A # Problem 4: **What is asked:** Determine which runner finished fourth (in order of finishing time). **Step 1 — Set Pedro's time as P (a reference).** Then: - Nico finished 11 minutes behind Pedro: Nico = P + 11. - Olympia finished 3 minutes behind Pedro: Olympia = P + 3. - Olympia finished 2 minutes ahead of Melina, so Melina = P + 3 + 2 = P + 5. - Olympia finished 6 minutes ahead of Luke, so Luke = P + 3 + 6 = P + 9. **Step 2 — Order from fastest to slowest:** Pedro (P), Olympia (P+3), Melina (P+5), Luke (P+9), Nico (P+11). **Step 3 — Fourth place** is **Luke**. **Rule out wrong answers:** Nico (C) is last (5th), Pedro (E) is first; a common error is swapping Luke and Melina — but Luke = P+9 is behind Melina = P+5. ANSWER 4: A # Problem 5: **What is asked:** Total time Walter spent on the bus (both ways). **Step 1 — Total elapsed time from 7:30 a.m. to 4:00 p.m.:** That is 8 hours 30 minutes = 510 minutes. **Step 2 — Time accounted for at school:** - Classes: 6 × 50 = 300 minutes - Lunch: 30 minutes - Additional time: 2 hours = 120 minutes - Total school time: 300 + 30 + 120 = 450 minutes. **Step 3 — Bus time:** 510 − 450 = **60 minutes**. **Rule out wrong answers:** 90 (D) would ignore lunch or additional time; 30 (A) would count only one bus ride — but the round trip must be 60 minutes total. ANSWER 5: B # Problem 6: **What is asked:** Find the total number of students. **Step 1 — Set up equations.** Let g = number of girls, b = number of boys. Each boy gets b beans (b boys), each girl gets g beans (g girls): b² + g² = 400 − 6 = 394, and b = g + 2. **Step 2 — Substitute and solve:** (g+2)² + g² = 394 g² + 4g + 4 + g² = 394 2g² + 4g − 390 = 0 g² + 2g − 195 = 0 (g + 15)(g − 13) = 0 → g = 13 (reject −15). **Step 3 — Find the total:** Boys: b = 13 + 2 = 15. Total students = 15 + 13 = **28**. **Check:** 15² + 13² = 225 + 169 = 394 = 400 − 6. ✓ ANSWER 6: B # Problem 7: **What is asked:** Miles each of the 5 tires was used over 30,000 miles. **Step 1 — Total tire-miles used:** At any moment the car uses 4 tires. Over 30,000 miles, total tire-miles = 4 × 30,000 = 120,000. **Step 2 — Split equally among 5 tires:** 120,000 ÷ 5 = **24,000 miles** each. **Rule out wrong answers:** 30,000 (D) is wrong because no single tire can be used the whole time when 5 tires share the work; 6,000 (A) and 7,500 (B) wrongly divide by the wrong quantity (e.g., 30,000 ÷ 5 or ÷ 4). ANSWER 7: C # Problem 8: **What is asked:** Sum of the two two-digit multiples of 7 whose digits sum to 10. **Step 1 — List two-digit multiples of 7 and digit sums:** 14 (5), 21 (3), **28 (10)** ✓, 35 (8), 42 (6), 49 (13), 56 (11), 63 (9), 70 (7), 77 (14), 84 (12), **91 (10)** ✓, 98 (17). **Step 2 — Identify the two qualifying numbers:** 28 and 91. **Step 3 — Sum:** 28 + 91 = **119**. **Rule out wrong answers:** 126 (B) is 63 + 63 — impossible since numbers are distinct; 140 (D) might come from 28 + 112 (but 112 is three digits). ANSWER 8: A # Problem 9: **What is asked:** Ratio of Alex's can volume to Felicia's can volume. **Step 1 — Volume formula:** V = πr²h. **Step 2 — Alex's can:** diameter 6 → radius 3; height 12. V_A = π(3)²(12) = 108π. **Step 3 — Felicia's can:** diameter 12 → radius 6; height 6. V_F = π(6)²(6) = 216π. **Step 4 — Ratio:** V_A : V_F = 108π : 216π = **1 : 2**. **Rule out wrong answers:** 1:1 (C) is the tempting "swapped dimensions" intuition, but volume depends on the *square* of the radius, so doubling the radius quadruples that factor while halving the height only halves — net effect is Felicia's can is twice as big. ANSWER 9: B # Problem 10: **What is asked:** Find the smallest number > 2 that leaves remainder 2 when divided by 3, 4, 5, and 6, and identify the interval containing it. **Step 1 — Interpret the condition:** N − 2 must be divisible by 3, 4, 5, and 6, i.e., N − 2 is a multiple of LCM(3, 4, 5, 6). **Step 2 — Compute the LCM:** LCM(3,4,5,6) = 60 (since 60 is divisible by 3, 4, 5, and 6). **Step 3 — Candidates:** N = 60k + 2 for whole numbers k: N = 2, 62, 122, ... The smallest *greater than 2* is **62**. **Step 4 — Locate 62:** It lies between **61 and 65**. **Rule out wrong answers:** 42 + 2 = 44 is a common error (using 42, the LCM of only |
openrouter:qwen/qwen3.8-27b |
A | ✓ | showProblem 1:
The dress is originally priced at \$80. A 25% discount means the sale price is
\[
80(1-0.25)=80(0.75)=60.
\]
Then 10% tax is added to the sale price:
\[
60(1+0.10)=60(1.10)=66.
\]
So the total selling price is \$66.
ANSWER 1: D
Problem 2:
Anh drove 10 miles on the coastal road in 30 minutes, so his coastal-road speed was
\[
\frac{10\text{ miles}}{30\text{ minutes}}.
\]
He drove three times as fast on the highway. Therefore, for the same distance, the highway time would be one-third as long.
For 50 miles on the highway, if he had driven at coastal-road speed, it would take
\[
30 \times \frac{50}{10}=150
\]
minutes. But because he drove three times as fast on the highway, the actual highway time is
\[
\frac{150}{3}=50
\]
minutes.
The coastal road took 30 minutes, so the total trip time was
\[
30+50=80
\]
minutes.
ANSWER 2: C
Problem 3:
The equation should be read as
\[
2^w \cdot 3^x \cdot 5^y \cdot 7^z = 588.
\]
Factor 588:
\[
588=2\cdot 294=2^2\cdot 147=2^2\cdot 3\cdot 49=2^2\cdot 3^1\cdot 7^2.
\]
There is no factor of 5, so \(y=0\). Comparing prime exponents gives
\[
w=2,\qquad x=1,\qquad y=0,\qquad z=2.
\]
Now compute
\[
2w+3x+5y+7z=2(2)+3(1)+5(0)+7(2).
\]
\[
=4+3+0+14=21.
\]
ANSWER 3: A
Problem 4:
Let Pedro’s finishing time be \(P\). In a race, a smaller time means finishing earlier.
- Nico finished 11 minutes behind Pedro, so Nico’s time is
\[
P+11.
\]
- Olympia finished 3 minutes behind Pedro, so Olympia’s time is
\[
P+3.
\]
- Olympia finished 2 minutes ahead of Melina, so Melina’s time is
\[
(P+3)+2=P+5.
\]
- Olympia finished 6 minutes ahead of Luke, so Luke’s time is
\[
(P+3)+6=P+9.
\]
Now order the runners from first to last by increasing time:
\[
P,\quad P+3,\quad P+5,\quad P+9,\quad P+11.
\]
That is:
1. Pedro
2. Olympia
3. Melina
4. Luke
5. Nico
So the fourth runner was Luke.
ANSWER 4: A
Problem 5:
From 7:30 a.m. to 4:00 p.m. is 8 hours and 30 minutes:
\[
8(60)+30=480+30=510
\]
minutes.
Walter’s time in school not spent on the bus is:
- 6 classes of 50 minutes each:
\[
6(50)=300
\]
minutes;
- lunch: 30 minutes;
- additional time: 2 hours = 120 minutes.
Total non-bus time:
\[
300+30+120=450
\]
minutes.
So his total bus time was
\[
510-450=60
\]
minutes.
ANSWER 5: B
Problem 6:
Let the number of girls be \(g\). Since there were two more boys than girls, the number of boys is
\[
g+2.
\]
Mrs. Awesome gave each boy as many jelly beans as there were boys, so the boys received
\[
(g+2)^2
\]
jelly beans total. Each girl received as many as there were girls, so the girls received
\[
g^2
\]
jelly beans total.
She had 400 jelly beans and 6 left, so she gave away
\[
400-6=394.
\]
Thus,
\[
(g+2)^2+g^2=394.
\]
Expand:
\[
g^2+4g+4+g^2=394
\]
\[
2g^2+4g+4=394
\]
\[
2g^2+4g-390=0
\]
Divide by 2:
\[
g^2+2g-195=0.
\]
Factor:
\[
(g+15)(g-13)=0.
\]
Since \(g\) must be positive,
\[
g=13.
\]
Then the number of boys is
\[
13+2=15.
\]
The total number of students is
\[
13+15=28.
\]
ANSWER 6: B
Problem 7:
During the first 30,000 miles, the car was always using 4 tires at once. Therefore, the total “tire-miles” used is
\[
4 \times 30{,}000=120{,}000.
\]
There are 5 tires total, and they were all used the same number of miles. So each tire was used for
\[
\frac{120{,}000}{5}=24{,}000
\]
miles.
ANSWER 7: C
Problem 8:
We need two-digit multiples of 7 whose digits sum to 10.
The two-digit multiples of 7 are:
\[
14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84, 91, 98.
\]
Check digit sums:
\[
14: 1+4=5
\]
\[
21: 2+1=3
\]
\[
28: 2+8=10
\]
\[
35: 3+5=8
\]
\[
42: 4+2=6
\]
\[
49: 4+9=13
\]
\[
56: 5+6=11
\]
\[
63: 6+3=9
\]
\[
70: 7+0=7
\]
\[
77: 7+7=14
\]
\[
84: 8+4=12
\]
\[
91: 9+1=10
\]
\[
98: 9+8=17
\]
The only two are 28 and 91. Their sum is
\[
28+91=119.
\]
ANSWER 8: A
Problem 9:
The volume of a cylinder is
\[
V=\pi r^2h.
\]
Alex’s cans have diameter 6 cm, so radius 3 cm, and height 12 cm:
\[
V_A=\pi(3^2)(12)=\pi(9)(12)=108\pi.
\]
Felicia’s cans have diameter 12 cm, so radius 6 cm, and height 6 cm:
\[
V_F=\pi(6^2)(6)=\pi(36)(6)=216\pi.
\]
The ratio of Alex’s can volume to Felicia’s can volume is
\[
108\pi:216\pi=108:216=1:2.
\]
ANSWER 9: B
Problem 10:
Let the number be \(N\). It leaves a remainder of 2 when divided by 3, 4, 5, and 6, so
\[
N-2
\]
is divisible by 3, 4, 5, and 6. Therefore, \(N-2\) must be a multiple of the least common multiple of 3, 4, 5, and 6.
Find the LCM:
\[
\operatorname{lcm}(3,4,5,6)=60.
\]
So
\[
N-2=60k
\]
for some positive integer \(k\), because we need \(N>2\).
The smallest possible value is when \(k=1\):
\[
N-2=60
\]
\[
N=62.
\]
This lies between 61 and 65.
ANSWER 10: D |
openrouter:anthropic/claude-opus-5 |
A | ✓ | showProblem 1: Sale price: 25% off means you pay 75%: 80 × 0.75 = 60 dollars. Add 10% tax: 60 × 1.10 = 66 dollars. (Choice C, 54, would come from subtracting 10%; choice D is correct. Note taking 25% off then adding 10% doesn't return to 80.) ANSWER 1: D Problem 2: Coastal road: 10 miles in 30 minutes, so 3 minutes per mile. Highway speed is 3 times as fast, so 1 minute per mile. Highway time: 50 miles × 1 minute/mile = 50 minutes. Total: 50 + 30 = 80 minutes. (Choice A forgets the coastal 30 minutes; choice D would come from using 3 min/mile on the highway incorrectly.) ANSWER 2: C Problem 3: The equation is 2^w · 3^x · 5^y · 7^z = 588. Factor 588 = 4 · 147 = 2² · 3 · 7². So w = 2, x = 1, y = 0, z = 2. Then 2w + 3x + 5y + 7z = 2(2) + 3(1) + 5(0) + 7(2) = 4 + 3 + 0 + 14 = 21. ANSWER 3: A Problem 4: Let Pedro's time be 0 (he's a reference). - Nico = +11 - Olympia = +3 (3 min behind Pedro) - Melina = Olympia + 2 = +5 - Luke = Olympia + 6 = +9 Order from first: Pedro (0), Olympia (3), Melina (5), Luke (9), Nico (11). Fourth place is Luke. ANSWER 4: A Problem 5: Total time away: 7:30 a.m. to 4:00 p.m. = 8 hours 30 minutes = 510 minutes. Time at school: classes 6 × 50 = 300, lunch 30, extra 2 hours = 120; total 450 minutes. Bus time = 510 − 450 = 60 minutes (both trips combined). ANSWER 5: B Problem 6: Let g = number of girls, b = g + 2 boys. Jelly beans used: b² + g² = 400 − 6 = 394. (g + 2)² + g² = 394 → 2g² + 4g + 4 = 394 → g² + 2g − 195 = 0 → (g + 15)(g − 13) = 0 → g = 13. So girls = 13, boys = 15; check 169 + 225 = 394 ✓. Total students = 28. ANSWER 6: B Problem 7: Four tires are on the road at any time, so total tire-miles = 4 × 30,000 = 120,000. Shared equally among 5 tires: 120,000 ÷ 5 = 24,000 miles each. (30,000 would be if no rotation; 6,000 is the rest time per tire, not use.) ANSWER 7: C Problem 8: Two-digit multiples of 7: 14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84, 91, 98. Digit sums: 5, 3, 10, 8, 6, 13, 11, 9, 7, 14, 12, 10, 17. Digit sum 10 occurs for 28 and 91. Sum: 28 + 91 = 119. ANSWER 8: A Problem 9: Alex: diameter 6 → radius 3, height 12: V = π(3²)(12) = 108π. Felicia: diameter 12 → radius 6, height 6: V = π(6²)(6) = 216π. Ratio = 108π : 216π = 1 : 2. (Doubling the radius quadruples volume, while halving height only halves it, so Felicia's is twice as big — not equal.) ANSWER 9: B Problem 10: A number leaving remainder 2 when divided by 3, 4, 5, and 6 must be 2 more than a common multiple of 3, 4, 5, 6. LCM(3, 4, 5, 6) = 60, so the smallest such number greater than 2 is 60 + 2 = 62. 62 lies between 61 and 65. ANSWER 10: D |
openrouter:openai/gpt-5.6-terra-pro |
A | ✓ | showProblem 1:
The dress was originally priced at \$80.
A 25% discount means the sale price is \(75\%\) of the original price:
\[
80 \times 0.75=60
\]
Then 10% tax is added:
\[
10\% \text{ of } 60 = 6
\]
So the total price is
\[
60+6=66
\]
A common mistake is to subtract 25% and add 10% of the original \$80, but the tax is added to the reduced sale price, not the original price.
\[
\boxed{66}
\]
ANSWER 1: D
Problem 2:
Anh drove 10 miles on the coastal road in 30 minutes.
Since 30 minutes is \(\frac12\) hour, his coastal-road speed was
\[
\frac{10\text{ miles}}{\frac12\text{ hour}}=20\text{ miles per hour}
\]
He drove three times as fast on the highway:
\[
3(20)=60\text{ miles per hour}
\]
The highway trip was 50 miles, so the highway driving time was
\[
\frac{50}{60}\text{ hour}=\frac56\text{ hour}
\]
Convert \(\frac56\) hour to minutes:
\[
\frac56\cdot 60=50\text{ minutes}
\]
His total driving time was
\[
30+50=80\text{ minutes}
\]
The answer is not 50 minutes, since that is only the highway time.
\[
\boxed{80}
\]
ANSWER 2: C
Problem 3:
We are told that
\[
2^w\cdot 3^x\cdot 5^y\cdot 7^z=588
\]
Factor 588 into primes:
\[
588=2\cdot 294=2^2\cdot 147=2^2\cdot 3\cdot 49
\]
Thus,
\[
588=2^2\cdot 3^1\cdot 5^0\cdot 7^2
\]
So
\[
w=2,\qquad x=1,\qquad y=0,\qquad z=2
\]
Now calculate:
\[
2w+3x+5y+7z
\]
\[
=2(2)+3(1)+5(0)+7(2)
\]
\[
=4+3+0+14=21
\]
The factor \(5^0\) is important: since 588 has no factor of 5, \(y=0\), not 1.
\[
\boxed{21}
\]
ANSWER 3: A
Problem 4:
We compare all runners’ finishing times relative to Pedro.
- Nico finished 11 minutes behind Pedro.
- Olympia finished 3 minutes behind Pedro.
- Olympia finished 2 minutes ahead of Melina, so Melina finished 2 minutes behind Olympia.
- Olympia finished 6 minutes ahead of Luke, so Luke finished 6 minutes behind Olympia.
Let Pedro finish at time 0.
Then:
\[
\begin{array}{c|c}
\text{Runner} & \text{Minutes behind Pedro} \\
\hline
\text{Pedro} & 0\\
\text{Olympia} & 3\\
\text{Melina} & 3+2=5\\
\text{Luke} & 3+6=9\\
\text{Nico} & 11
\end{array}
\]
Therefore, the order is:
1. Pedro
2. Olympia
3. Melina
4. Luke
5. Nico
So Luke finished fourth.
\[
\boxed{\text{Luke}}
\]
ANSWER 4: A
Problem 5:
Walter is at school from 7:30 a.m. until 4:00 p.m.
That is:
\[
8\text{ hours }30\text{ minutes}=510\text{ minutes}
\]
His school-day activities take:
- 6 classes of 50 minutes each:
\[
6\cdot 50=300\text{ minutes}
\]
- Lunch:
\[
30\text{ minutes}
\]
- Additional school time:
\[
2\text{ hours}=120\text{ minutes}
\]
Total time not spent on the bus:
\[
300+30+120=450\text{ minutes}
\]
Therefore, bus time is
\[
510-450=60\text{ minutes}
\]
This includes both the ride to school and the ride home.
\[
\boxed{60}
\]
ANSWER 5: B
Problem 6:
Let the number of girls be \(g\).
There are two more boys than girls, so the number of boys is
\[
g+2
\]
Each boy receives as many jelly beans as there are boys, so the boys receive
\[
(g+2)(g+2)=(g+2)^2
\]
jelly beans altogether.
Each girl receives \(g\) jelly beans, so the girls receive
\[
g^2
\]
jelly beans altogether.
Mrs. Awesome gave away
\[
400-6=394
\]
jelly beans. Therefore,
\[
g^2+(g+2)^2=394
\]
Expand:
\[
g^2+g^2+4g+4=394
\]
\[
2g^2+4g-390=0
\]
Divide by 2:
\[
g^2+2g-195=0
\]
Factor:
\[
(g+15)(g-13)=0
\]
So
\[
g=13
\]
since a number of girls cannot be negative.
Thus boys:
\[
13+2=15
\]
Total students:
\[
13+15=28
\]
\[
\boxed{28}
\]
ANSWER 6: B
Problem 7:
During the first 30,000 miles, the car always uses 4 tires on the road.
So the total number of tire-miles used is
\[
4\cdot 30{,}000=120{,}000
\]
There are 5 tires total, and they were rotated so each tire was used equally.
Therefore, each tire was used
\[
\frac{120{,}000}{5}=24{,}000
\]
miles.
It is not 30,000 miles because only four of the five tires are being driven on at any one time.
\[
\boxed{24{,}000}
\]
ANSWER 7: C
Problem 8:
We need two-digit multiples of 7 whose digits add to 10.
The two-digit multiples of 7 are:
\[
14,21,28,35,42,49,56,63,70,77,84,91,98
\]
Check digit sums:
\[
28:\quad 2+8=10
\]
\[
91:\quad 9+1=10
\]
These are the only two.
Their sum is
\[
28+91=119
\]
\[
\boxed{119}
\]
ANSWER 8: A
Problem 9:
The volume of a cylinder is
\[
V=\pi r^2h
\]
For Alex’s can:
- Diameter \(=6\), so radius \(=3\)
- Height \(=12\)
\[
V_A=\pi(3)^2(12)=108\pi
\]
For Felicia’s can:
- Diameter \(=12\), so radius \(=6\)
- Height \(=6\)
\[
V_F=\pi(6)^2(6)=216\pi
\]
The ratio of Alex’s volume to Felicia’s volume is
\[
108\pi:216\pi
\]
Divide both parts by \(108\pi\):
\[
1:2
\]
Although Alex’s can is twice as tall, Felicia’s radius is twice as large, and radius is squared in the volume formula.
\[
\boxed{1:2}
\]
ANSWER 9: B
Problem 10:
We seek the smallest number greater than 2 that leaves remainder 2 when divided by 3, 4, 5, and 6.
If the number is \(n\), then \(n-2\) must be divisible by all of
\[
3,\ 4,\ 5,\ 6
\]
The least common multiple is
\[
\operatorname{lcm}(3,4,5,6)=60
\]
So the smallest possible value of \(n-2\) is 60:
\[
n-2=60
\]
\[
n=62
\]
The number 62 lies between 61 and 65.
Indeed:
\[
62\div 3,\ 62\div 4,\ 62\div 5,\ 62\div 6
\]
all leave remainder 2.
\[
\boxed{61\text{ and }65}
\]
ANSWER 10: D |
Five runners finished a race: Luke, Melina, Nico, Olympia, and Pedro. Nico finished 11 minutes behind Pedro. Olympia finished 2 minutes ahead of Melina but 3 minutes behind Pedro. Olympia finished 6 minutes ahead of Luke. Which runner finished fourth?
| Model | Pick | ✓/✗ | Reasoning |
|---|---|---|---|
openrouter:meta/muse-spark-1.3 |
A | ✓ | showProblem 1: We are asked for the final price after a discount and then tax. Original price is 80 dollars. 25% off means pay 100% - 25% = 75% of original. Sale price = 0.75 × 80 = 60 dollars. Tempting mistake: subtract 25 dollars to get 55. No, 25% means percent, not dollars. Then 10% tax is added to the sale price, not the original price. Tax = 10% of 60 = 6 dollars. Total = 60 + 6 = 66 dollars. Equivalently 1.10 × 60 = 66. Check: A 45 is far too low. B 52 would be 35% off total. C 54 would be adding tax incorrectly. E 68 would be adding 10% of 80. ANSWER 1: D Problem 2: We need total time = time on coastal road + time on highway. Given time on coastal road = 30 minutes for 10 miles. Let coastal speed = v. Then v = 10 miles / 30 min. Highway speed is three times as fast: 3v. Highway distance is 50 miles. Time = distance / speed, so: Highway time = 50 / (3v). From coastal: 10 / v = 30, so 1/v = 3 min per mile. Thus highway time = 50 / 3 × (1/v) = 50/3 × 3 = 50 minutes. Total = 30 + 50 = 80 minutes. Alternative check: Highway is 5 times distance but 3 times speed, so takes 5/3 as long as coastal: 30 × 5/3 = 50. ANSWER 2: C Problem 3: We are told w,x,y,z are whole numbers, so 0,1,2,... And 2^w · 3^x · 5^y · 7^z = 588. Find 2w + 3x + 5y + 7z. Factor 588 into primes. 588 = 58.8 × 10, but do integer: 588 = 2 × 294 = 2 × 2 × 147 = 4 × 147. 147 = 3 × 49 = 3 × 7 × 7. So 588 = 2^2 × 3^1 × 5^0 × 7^2. By uniqueness of prime factorization, exponents must match: w = 2, x = 1, y = 0, z = 2. Note y=0 is allowed because whole numbers include 0, and 5^0 = 1. Now compute linear expression: 2w + 3x + 5y + 7z = 2×2 + 3×1 + 5×0 + 7×2 = 4 + 3 + 0 + 14 = 21. ANSWER 3: A Problem 4: Order the five finishers by time behind Pedro. Let Pedro's time be P. Nico finished 11 minutes behind Pedro: N = P+11. Olympia finished 3 minutes behind Pedro: O = P+3. Olympia finished 2 minutes ahead of Melina: So Melina is 2 minutes behind Olympia: M = O+2 = P+5. Olympia finished 6 minutes ahead of Luke: So Luke is 6 minutes behind Olympia: L = O+6 = P+9. Order by increasing time: Pedro at P+0 — 1st Olympia at P+3 — 2nd Melina at P+5 — 3rd Luke at P+9 — 4th Nico at P+11 — 5th So fourth is Luke. ANSWER 4: A Problem 5: Total elapsed time from boarding morning bus to arriving home. From 7:30 a.m. to 4:00 p.m. = 8.5 hours = 8×60 + 30 = 510 minutes. Time at school: 6 classes × 50 min = 300 min. Lunch 30 min. Additional 2 hours = 120 min. Total school = 300 + 30 + 120 = 450 min. Bus time (morning + afternoon) = total elapsed - school time = 510 - 450 = 60 minutes. Tempting error: miscount 7:30 to 4:00 as 8 hours. ANSWER 5: B Problem 6: Let g = number of girls. Then number of boys b = g+2. Each boy gets b beans, so boys total = b × b = b^2. Each girl gets g beans, so girls total = g × g = g^2. Beans used = 400 - 6 left = 394. So b^2 + g^2 = 394. Substitute: (g+2)^2 + g^2 = 394 g^2 + 4g + 4 + g^2 = 394 2g^2 + 4g - 390 = 0 Divide 2: g^2 + 2g - 195 = 0. Factor 195 = 13 × 15, differing by 2: (g+15)(g-13)=0. Positive solution g = 13. Then b = 15. Total students = 13+15 = 28. Check: 15^2+13^2 =225+169=394 correct. ANSWER 6: B Problem 7: The car travels 30,000 miles. At any moment exactly 4 tires are on the road carrying it. Total tire-miles delivered = 4 tires × 30,000 miles = 120,000 tire-miles. This wear is shared equally among 5 tires by rotation. Per tire = 120,000 / 5 = 24,000 miles. Tempting wrong: 30,000/5 = 6,000 ignores that 4 tires are used at once. 30,000 would mean no rotation. ANSWER 7: C Problem 8: List two-digit multiples of 7: 14,21,28,35,42,49,56,63,70,77,84,91,98. Compute digit sums: 1+4=5, 2+1=3, 2+8=10, 3+5=8, 4+2=6, 4+9=13, 5+6=11, 6+3=9, 7+0=7, 7+7=14, 8+4=12, 9+1=10, 9+8=17. Only two have sum 10: 28 and 91. Their sum = 28+91 = 119. ANSWER 8: A Problem 9: Volume of cylinder = π r^2 h, where r = diameter/2. Alex: diameter 6, so r=3. height 12. V_A = π × 3^2 × 12 = π × 9 × 12 = 108π. Felicia: diameter 12, so r=6. height 6. V_F = π × 6^2 × 6 = π × 36 × 6 = 216π. Ratio V_A : V_F = 108π : 216π = 108:216 = 1:2. Note volume scales with square of radius, so doubling diameter quadruples base area, outweighing halving height. ANSWER 9: B Problem 10: We need N > 2 with N ≡ 2 mod 3, mod 4, mod 5, mod 6. So N-2 is divisible by each of 3,4,5,6. N-2 must be a common multiple of 3,4,5,6. LCM(3,4,5,6): 4=2^2, 6=2×3, so LCM = 2^2 × 3 × 5 = 60. Positive multiples: 60,120,... N=2 gives N-2=0 which works but is excluded by >2. Next smallest is N-2 = 60, so N = 62. 62 is between 61 and 65. Check: 62 ÷ 3 =20 rem 2, ÷4=15 rem 2, etc. ANSWER 10: D |
openrouter:google/gemini-3.8-flash |
A | ✓ | showProblem 1:
**Restatement and Setup:**
We are given an item with an original price of $\$80$. It is discounted by $25\%$, and then a $10\%$ sales tax is applied to this discounted sale price. We need to find the final total selling price.
**Step-by-step computation:**
1. Calculate the discount:
$$\text{Discount} = 25\% \text{ of } \$80 = 0.25 \times 80 = \$20$$
2. Calculate the sale price:
$$\text{Sale Price} = \$80 - \$20 = \$60$$
*(Alternatively, the sale price is $75\%$ of $\$80$: $0.75 \times 80 = \$60$.)*
3. Calculate the tax on the sale price:
$$\text{Tax} = 10\% \text{ of } \$60 = 0.10 \times 60 = \$6$$
4. Calculate the total price:
$$\text{Total Price} = \$60 + \$6 = \$66$$
**Ruling out wrong choices:**
- Choice A ($\$45$) results from incorrectly subtracting both $25\%$ and $10\%$ from the original price, or similar errors.
- Choice B ($\$52$) and Choice C ($\$54$) are too low.
- Choice E ($\$68$) might occur if the tax were incorrectly computed on the original $\$80$ price ($80 \times 0.10 = \$8$) and added to $\$60$.
ANSWER 1: D
---
Problem 2:
**Restatement and Setup:**
Anh drives on two segments:
- Coastal access road: distance $d_c = 10$ miles, time $t_c = 30$ minutes.
- Highway: distance $d_h = 50$ miles.
He drives three times as fast on the highway as on the coastal access road ($v_h = 3 v_c$). We need to find the total time in minutes for the entire trip.
**Step-by-step computation:**
1. Find the speed on the coastal road:
Anh drives $10$ miles in $30$ minutes ($0.5$ hours).
$$v_c = \frac{10\text{ miles}}{0.5\text{ hours}} = 20\text{ mph}$$
2. Find the speed on the highway:
$$v_h = 3 \times v_c = 3 \times 20\text{ mph} = 60\text{ mph} = 1\text{ mile per minute}$$
3. Find the time spent on the highway:
$$t_h = \frac{50\text{ miles}}{1\text{ mile per minute}} = 50\text{ minutes}$$
4. Find the total trip time:
$$\text{Total time} = t_c + t_h = 30\text{ minutes} + 50\text{ minutes} = 80\text{ minutes}$$
**Ruling out wrong choices:**
- Choice A ($50$) is just the time on the highway.
- Choices B ($70$), D ($90$), and E ($100$) arise from miscalculating the highway speed ratio or mixing up minutes and hours.
ANSWER 2: C
---
Problem 3:
**Restatement and Setup:**
Given whole numbers (non-negative integers) $w, x, y, z$ such that:
$$2^w \cdot 3^x \cdot 5^y \cdot 7^z = 588$$
We need to find the value of $2w + 3x + 5y + 7z$.
**Step-by-step computation:**
1. Find the prime factorization of $588$:
$$588 = 2 \times 294 = 2 \times 2 \times 147 = 4 \times 3 \times 49 = 2^2 \times 3^1 \times 7^2$$
2. Matching the prime factors with $2^w \cdot 3^x \cdot 5^y \cdot 7^z$:
- $w = 2$
- $x = 1$
- $y = 0$ (since $5$ is not a factor of $588$)
- $z = 2$
3. Compute the required expression $2w + 3x + 5y + 7z$:
$$2(2) + 3(1) + 5(0) + 7(2) = 4 + 3 + 0 + 14 = 21$$
**Ruling out wrong choices:**
- If one mistakenly sets $y=1$, the sum would be $21 + 5 = 26$ (close to 25 or 27).
- Choices B, C, D, and E do not match the evaluated sum of $21$.
ANSWER 3: A
---
Problem 4:
**Restatement and Setup:**
Five runners (Luke, Melina, Nico, Olympia, Pedro) finished a race. We are given relative finish times:
- Nico finished $11$ minutes behind Pedro.
- Olympia finished $3$ minutes behind Pedro.
- Olympia finished $2$ minutes ahead of Melina.
- Olympia finished $6$ minutes ahead of Luke.
We need to determine who finished in fourth place.
**Step-by-step computation:**
Let Pedro's finish time be $t=0$ minutes (the earliest/winner).
- Pedro finishes at $0$ minutes.
- Olympia finished $3$ minutes behind Pedro $\implies$ Olympia finishes at $0 + 3 = 3$ minutes.
- Olympia finished $2$ minutes ahead of Melina $\implies$ Melina finishes $2$ minutes after Olympia $\implies 3 + 2 = 5$ minutes.
- Olympia finished $6$ minutes ahead of Luke $\implies$ Luke finishes $6$ minutes after Olympia $\implies 3 + 6 = 9$ minutes.
- Nico finished $11$ minutes behind Pedro $\implies$ Nico finishes at $0 + 11 = 11$ minutes.
Listing the runners in order of finish:
1. Pedro ($0$ min)
2. Olympia ($3$ min)
3. Melina ($5$ min)
4. Luke ($9$ min)
5. Nico ($11$ min)
Thus, Luke finished fourth.
**Ruling out wrong choices:**
- Pedro was 1st, Olympia was 2nd, Melina was 3rd, and Nico was 5th (last).
ANSWER 4: A
---
Problem 5:
**Restatement and Setup:**
Walter boards the bus at 7:30 a.m. and arrives home from the bus at 4:00 p.m.
During the day, he spends time on the bus (both ways) and at school.
School activities consist of:
- $6$ classes of $50$ minutes each
- $30$ minutes for lunch
- $2$ hours of additional time
We need to find the total time Walter spent on the bus.
**Step-by-step computation:**
1. Calculate total elapsed time between leaving home and returning:
- From 7:30 a.m. to 12:00 p.m. is $4$ hours and $30$ minutes ($4.5$ hours).
- From 12:00 p.m. to 4:00 p.m. is $4$ hours.
- Total elapsed time = $8$ hours and $30$ minutes $= 8 \times 60 + 30 = 510$ minutes.
2. Calculate total time spent on school activities:
- Classes: $6 \times 50\text{ minutes} = 300\text{ minutes}$
- Lunch: $30\text{ minutes}$
- Additional time: $2\text{ hours} = 120\text{ minutes}$
- Total school time $= 300 + 30 + 120 = 450\text{ minutes}$.
3. Calculate time spent on the bus:
$$\text{Bus time} = \text{Total time} - \text{School time} = 510 - 450 = 60\text{ minutes}$$
**Ruling out wrong choices:**
- 30 minutes assumes only a one-way trip or forgets additional school time.
- 75, 90, 120 minutes result from miscounting the elapsed time or forgetting the 30-minute lunch.
ANSWER 5: B
---
Problem 6:
**Restatement and Setup:**
Let $b$ be the number of boys and $g$ be the number of girls.
- Each boy receives $b$ jelly beans (total $b^2$).
- Each girl receives $g$ jelly beans (total $g^2$).
- Total jelly beans distributed: $400 - 6 = 394$.
- There are two more boys than girls: $b = g + 2$.
We need to find the total number of students in the class, which is $b + g$.
**Step-by-step com |
openrouter:~z-ai/glm-latest |
A | ✓ | show# Problem 1: **What is asked:** Find the final price after a 25% discount on $80, followed by 10% tax on the *sale price*. **Step 1 — Compute the sale price (25% off):** Discount = 25% of 80 = 0.25 × 80 = $20. Sale price = 80 − 20 = **$60**. **Step 2 — Add 10% tax to the sale price:** Tax = 10% of 60 = $6. Total = 60 + 6 = **$66**. **Rule out wrong answers:** - $52 (B) comes from wrongly taking 10% off the *original* price (60 − 8), but tax is added, not discounted. - $54 (C) comes from adding discounts: 80 × 0.75 × 0.9 — but tax increases the price. - The correct sequence is 80 → 60 → 66. ANSWER 1: D # Problem 2: **What is asked:** Find the total driving time in minutes. **Step 1 — Coastal road speed:** Anh drove 10 miles in 30 minutes (= 0.5 hour). Speed = 10 ÷ 0.5 = **20 mph**. **Step 2 — Highway speed:** He drove 3 times as fast: 3 × 20 = **60 mph**. **Step 3 — Highway time:** Time = distance ÷ speed = 50 ÷ 60 = 5/6 hour = **50 minutes**. **Step 4 — Total time:** 30 + 50 = **80 minutes**. **Rule out wrong answers:** - 90 (D) would result from wrongly assuming equal speeds (30 min + 60 min); but the highway was faster, so its time is *less* than 60 minutes. Only 80 fits. ANSWER 2: C # Problem 3: **What is asked:** Given 2^w · 3^x · 5^y · 7^z = 588, find 2w + 3x + 5y + 7z. **Step 1 — Factor 588:** 588 = 4 × 147 = 4 × 3 × 49 = 2² × 3 × 7². **Step 2 — Read off exponents:** 588 = 2² · 3¹ · 5⁰ · 7², so w = 2, x = 1, y = 0, z = 2. **Step 3 — Compute the expression:** 2w + 3x + 5y + 7z = 2(2) + 3(1) + 5(0) + 7(2) = 4 + 3 + 0 + 14 = **21**. **Rule out wrong answers:** 35 (D) or 56 (E) would come from confusing the coefficients 2,3,5,7 with the bases; note 588 is not divisible by 5, forcing y = 0. ANSWER 3: A # Problem 4: **What is asked:** Determine which runner finished fourth (in order of finishing time). **Step 1 — Set Pedro's time as P (a reference).** Then: - Nico finished 11 minutes behind Pedro: Nico = P + 11. - Olympia finished 3 minutes behind Pedro: Olympia = P + 3. - Olympia finished 2 minutes ahead of Melina, so Melina = P + 3 + 2 = P + 5. - Olympia finished 6 minutes ahead of Luke, so Luke = P + 3 + 6 = P + 9. **Step 2 — Order from fastest to slowest:** Pedro (P), Olympia (P+3), Melina (P+5), Luke (P+9), Nico (P+11). **Step 3 — Fourth place** is **Luke**. **Rule out wrong answers:** Nico (C) is last (5th), Pedro (E) is first; a common error is swapping Luke and Melina — but Luke = P+9 is behind Melina = P+5. ANSWER 4: A # Problem 5: **What is asked:** Total time Walter spent on the bus (both ways). **Step 1 — Total elapsed time from 7:30 a.m. to 4:00 p.m.:** That is 8 hours 30 minutes = 510 minutes. **Step 2 — Time accounted for at school:** - Classes: 6 × 50 = 300 minutes - Lunch: 30 minutes - Additional time: 2 hours = 120 minutes - Total school time: 300 + 30 + 120 = 450 minutes. **Step 3 — Bus time:** 510 − 450 = **60 minutes**. **Rule out wrong answers:** 90 (D) would ignore lunch or additional time; 30 (A) would count only one bus ride — but the round trip must be 60 minutes total. ANSWER 5: B # Problem 6: **What is asked:** Find the total number of students. **Step 1 — Set up equations.** Let g = number of girls, b = number of boys. Each boy gets b beans (b boys), each girl gets g beans (g girls): b² + g² = 400 − 6 = 394, and b = g + 2. **Step 2 — Substitute and solve:** (g+2)² + g² = 394 g² + 4g + 4 + g² = 394 2g² + 4g − 390 = 0 g² + 2g − 195 = 0 (g + 15)(g − 13) = 0 → g = 13 (reject −15). **Step 3 — Find the total:** Boys: b = 13 + 2 = 15. Total students = 15 + 13 = **28**. **Check:** 15² + 13² = 225 + 169 = 394 = 400 − 6. ✓ ANSWER 6: B # Problem 7: **What is asked:** Miles each of the 5 tires was used over 30,000 miles. **Step 1 — Total tire-miles used:** At any moment the car uses 4 tires. Over 30,000 miles, total tire-miles = 4 × 30,000 = 120,000. **Step 2 — Split equally among 5 tires:** 120,000 ÷ 5 = **24,000 miles** each. **Rule out wrong answers:** 30,000 (D) is wrong because no single tire can be used the whole time when 5 tires share the work; 6,000 (A) and 7,500 (B) wrongly divide by the wrong quantity (e.g., 30,000 ÷ 5 or ÷ 4). ANSWER 7: C # Problem 8: **What is asked:** Sum of the two two-digit multiples of 7 whose digits sum to 10. **Step 1 — List two-digit multiples of 7 and digit sums:** 14 (5), 21 (3), **28 (10)** ✓, 35 (8), 42 (6), 49 (13), 56 (11), 63 (9), 70 (7), 77 (14), 84 (12), **91 (10)** ✓, 98 (17). **Step 2 — Identify the two qualifying numbers:** 28 and 91. **Step 3 — Sum:** 28 + 91 = **119**. **Rule out wrong answers:** 126 (B) is 63 + 63 — impossible since numbers are distinct; 140 (D) might come from 28 + 112 (but 112 is three digits). ANSWER 8: A # Problem 9: **What is asked:** Ratio of Alex's can volume to Felicia's can volume. **Step 1 — Volume formula:** V = πr²h. **Step 2 — Alex's can:** diameter 6 → radius 3; height 12. V_A = π(3)²(12) = 108π. **Step 3 — Felicia's can:** diameter 12 → radius 6; height 6. V_F = π(6)²(6) = 216π. **Step 4 — Ratio:** V_A : V_F = 108π : 216π = **1 : 2**. **Rule out wrong answers:** 1:1 (C) is the tempting "swapped dimensions" intuition, but volume depends on the *square* of the radius, so doubling the radius quadruples that factor while halving the height only halves — net effect is Felicia's can is twice as big. ANSWER 9: B # Problem 10: **What is asked:** Find the smallest number > 2 that leaves remainder 2 when divided by 3, 4, 5, and 6, and identify the interval containing it. **Step 1 — Interpret the condition:** N − 2 must be divisible by 3, 4, 5, and 6, i.e., N − 2 is a multiple of LCM(3, 4, 5, 6). **Step 2 — Compute the LCM:** LCM(3,4,5,6) = 60 (since 60 is divisible by 3, 4, 5, and 6). **Step 3 — Candidates:** N = 60k + 2 for whole numbers k: N = 2, 62, 122, ... The smallest *greater than 2* is **62**. **Step 4 — Locate 62:** It lies between **61 and 65**. **Rule out wrong answers:** 42 + 2 = 44 is a common error (using 42, the LCM of only |
openrouter:qwen/qwen3.8-27b |
A | ✓ | showProblem 1:
The dress is originally priced at \$80. A 25% discount means the sale price is
\[
80(1-0.25)=80(0.75)=60.
\]
Then 10% tax is added to the sale price:
\[
60(1+0.10)=60(1.10)=66.
\]
So the total selling price is \$66.
ANSWER 1: D
Problem 2:
Anh drove 10 miles on the coastal road in 30 minutes, so his coastal-road speed was
\[
\frac{10\text{ miles}}{30\text{ minutes}}.
\]
He drove three times as fast on the highway. Therefore, for the same distance, the highway time would be one-third as long.
For 50 miles on the highway, if he had driven at coastal-road speed, it would take
\[
30 \times \frac{50}{10}=150
\]
minutes. But because he drove three times as fast on the highway, the actual highway time is
\[
\frac{150}{3}=50
\]
minutes.
The coastal road took 30 minutes, so the total trip time was
\[
30+50=80
\]
minutes.
ANSWER 2: C
Problem 3:
The equation should be read as
\[
2^w \cdot 3^x \cdot 5^y \cdot 7^z = 588.
\]
Factor 588:
\[
588=2\cdot 294=2^2\cdot 147=2^2\cdot 3\cdot 49=2^2\cdot 3^1\cdot 7^2.
\]
There is no factor of 5, so \(y=0\). Comparing prime exponents gives
\[
w=2,\qquad x=1,\qquad y=0,\qquad z=2.
\]
Now compute
\[
2w+3x+5y+7z=2(2)+3(1)+5(0)+7(2).
\]
\[
=4+3+0+14=21.
\]
ANSWER 3: A
Problem 4:
Let Pedro’s finishing time be \(P\). In a race, a smaller time means finishing earlier.
- Nico finished 11 minutes behind Pedro, so Nico’s time is
\[
P+11.
\]
- Olympia finished 3 minutes behind Pedro, so Olympia’s time is
\[
P+3.
\]
- Olympia finished 2 minutes ahead of Melina, so Melina’s time is
\[
(P+3)+2=P+5.
\]
- Olympia finished 6 minutes ahead of Luke, so Luke’s time is
\[
(P+3)+6=P+9.
\]
Now order the runners from first to last by increasing time:
\[
P,\quad P+3,\quad P+5,\quad P+9,\quad P+11.
\]
That is:
1. Pedro
2. Olympia
3. Melina
4. Luke
5. Nico
So the fourth runner was Luke.
ANSWER 4: A
Problem 5:
From 7:30 a.m. to 4:00 p.m. is 8 hours and 30 minutes:
\[
8(60)+30=480+30=510
\]
minutes.
Walter’s time in school not spent on the bus is:
- 6 classes of 50 minutes each:
\[
6(50)=300
\]
minutes;
- lunch: 30 minutes;
- additional time: 2 hours = 120 minutes.
Total non-bus time:
\[
300+30+120=450
\]
minutes.
So his total bus time was
\[
510-450=60
\]
minutes.
ANSWER 5: B
Problem 6:
Let the number of girls be \(g\). Since there were two more boys than girls, the number of boys is
\[
g+2.
\]
Mrs. Awesome gave each boy as many jelly beans as there were boys, so the boys received
\[
(g+2)^2
\]
jelly beans total. Each girl received as many as there were girls, so the girls received
\[
g^2
\]
jelly beans total.
She had 400 jelly beans and 6 left, so she gave away
\[
400-6=394.
\]
Thus,
\[
(g+2)^2+g^2=394.
\]
Expand:
\[
g^2+4g+4+g^2=394
\]
\[
2g^2+4g+4=394
\]
\[
2g^2+4g-390=0
\]
Divide by 2:
\[
g^2+2g-195=0.
\]
Factor:
\[
(g+15)(g-13)=0.
\]
Since \(g\) must be positive,
\[
g=13.
\]
Then the number of boys is
\[
13+2=15.
\]
The total number of students is
\[
13+15=28.
\]
ANSWER 6: B
Problem 7:
During the first 30,000 miles, the car was always using 4 tires at once. Therefore, the total “tire-miles” used is
\[
4 \times 30{,}000=120{,}000.
\]
There are 5 tires total, and they were all used the same number of miles. So each tire was used for
\[
\frac{120{,}000}{5}=24{,}000
\]
miles.
ANSWER 7: C
Problem 8:
We need two-digit multiples of 7 whose digits sum to 10.
The two-digit multiples of 7 are:
\[
14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84, 91, 98.
\]
Check digit sums:
\[
14: 1+4=5
\]
\[
21: 2+1=3
\]
\[
28: 2+8=10
\]
\[
35: 3+5=8
\]
\[
42: 4+2=6
\]
\[
49: 4+9=13
\]
\[
56: 5+6=11
\]
\[
63: 6+3=9
\]
\[
70: 7+0=7
\]
\[
77: 7+7=14
\]
\[
84: 8+4=12
\]
\[
91: 9+1=10
\]
\[
98: 9+8=17
\]
The only two are 28 and 91. Their sum is
\[
28+91=119.
\]
ANSWER 8: A
Problem 9:
The volume of a cylinder is
\[
V=\pi r^2h.
\]
Alex’s cans have diameter 6 cm, so radius 3 cm, and height 12 cm:
\[
V_A=\pi(3^2)(12)=\pi(9)(12)=108\pi.
\]
Felicia’s cans have diameter 12 cm, so radius 6 cm, and height 6 cm:
\[
V_F=\pi(6^2)(6)=\pi(36)(6)=216\pi.
\]
The ratio of Alex’s can volume to Felicia’s can volume is
\[
108\pi:216\pi=108:216=1:2.
\]
ANSWER 9: B
Problem 10:
Let the number be \(N\). It leaves a remainder of 2 when divided by 3, 4, 5, and 6, so
\[
N-2
\]
is divisible by 3, 4, 5, and 6. Therefore, \(N-2\) must be a multiple of the least common multiple of 3, 4, 5, and 6.
Find the LCM:
\[
\operatorname{lcm}(3,4,5,6)=60.
\]
So
\[
N-2=60k
\]
for some positive integer \(k\), because we need \(N>2\).
The smallest possible value is when \(k=1\):
\[
N-2=60
\]
\[
N=62.
\]
This lies between 61 and 65.
ANSWER 10: D |
openrouter:anthropic/claude-opus-5 |
A | ✓ | showProblem 1: Sale price: 25% off means you pay 75%: 80 × 0.75 = 60 dollars. Add 10% tax: 60 × 1.10 = 66 dollars. (Choice C, 54, would come from subtracting 10%; choice D is correct. Note taking 25% off then adding 10% doesn't return to 80.) ANSWER 1: D Problem 2: Coastal road: 10 miles in 30 minutes, so 3 minutes per mile. Highway speed is 3 times as fast, so 1 minute per mile. Highway time: 50 miles × 1 minute/mile = 50 minutes. Total: 50 + 30 = 80 minutes. (Choice A forgets the coastal 30 minutes; choice D would come from using 3 min/mile on the highway incorrectly.) ANSWER 2: C Problem 3: The equation is 2^w · 3^x · 5^y · 7^z = 588. Factor 588 = 4 · 147 = 2² · 3 · 7². So w = 2, x = 1, y = 0, z = 2. Then 2w + 3x + 5y + 7z = 2(2) + 3(1) + 5(0) + 7(2) = 4 + 3 + 0 + 14 = 21. ANSWER 3: A Problem 4: Let Pedro's time be 0 (he's a reference). - Nico = +11 - Olympia = +3 (3 min behind Pedro) - Melina = Olympia + 2 = +5 - Luke = Olympia + 6 = +9 Order from first: Pedro (0), Olympia (3), Melina (5), Luke (9), Nico (11). Fourth place is Luke. ANSWER 4: A Problem 5: Total time away: 7:30 a.m. to 4:00 p.m. = 8 hours 30 minutes = 510 minutes. Time at school: classes 6 × 50 = 300, lunch 30, extra 2 hours = 120; total 450 minutes. Bus time = 510 − 450 = 60 minutes (both trips combined). ANSWER 5: B Problem 6: Let g = number of girls, b = g + 2 boys. Jelly beans used: b² + g² = 400 − 6 = 394. (g + 2)² + g² = 394 → 2g² + 4g + 4 = 394 → g² + 2g − 195 = 0 → (g + 15)(g − 13) = 0 → g = 13. So girls = 13, boys = 15; check 169 + 225 = 394 ✓. Total students = 28. ANSWER 6: B Problem 7: Four tires are on the road at any time, so total tire-miles = 4 × 30,000 = 120,000. Shared equally among 5 tires: 120,000 ÷ 5 = 24,000 miles each. (30,000 would be if no rotation; 6,000 is the rest time per tire, not use.) ANSWER 7: C Problem 8: Two-digit multiples of 7: 14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84, 91, 98. Digit sums: 5, 3, 10, 8, 6, 13, 11, 9, 7, 14, 12, 10, 17. Digit sum 10 occurs for 28 and 91. Sum: 28 + 91 = 119. ANSWER 8: A Problem 9: Alex: diameter 6 → radius 3, height 12: V = π(3²)(12) = 108π. Felicia: diameter 12 → radius 6, height 6: V = π(6²)(6) = 216π. Ratio = 108π : 216π = 1 : 2. (Doubling the radius quadruples volume, while halving height only halves it, so Felicia's is twice as big — not equal.) ANSWER 9: B Problem 10: A number leaving remainder 2 when divided by 3, 4, 5, and 6 must be 2 more than a common multiple of 3, 4, 5, 6. LCM(3, 4, 5, 6) = 60, so the smallest such number greater than 2 is 60 + 2 = 62. 62 lies between 61 and 65. ANSWER 10: D |
openrouter:openai/gpt-5.6-terra-pro |
A | ✓ | showProblem 1:
The dress was originally priced at \$80.
A 25% discount means the sale price is \(75\%\) of the original price:
\[
80 \times 0.75=60
\]
Then 10% tax is added:
\[
10\% \text{ of } 60 = 6
\]
So the total price is
\[
60+6=66
\]
A common mistake is to subtract 25% and add 10% of the original \$80, but the tax is added to the reduced sale price, not the original price.
\[
\boxed{66}
\]
ANSWER 1: D
Problem 2:
Anh drove 10 miles on the coastal road in 30 minutes.
Since 30 minutes is \(\frac12\) hour, his coastal-road speed was
\[
\frac{10\text{ miles}}{\frac12\text{ hour}}=20\text{ miles per hour}
\]
He drove three times as fast on the highway:
\[
3(20)=60\text{ miles per hour}
\]
The highway trip was 50 miles, so the highway driving time was
\[
\frac{50}{60}\text{ hour}=\frac56\text{ hour}
\]
Convert \(\frac56\) hour to minutes:
\[
\frac56\cdot 60=50\text{ minutes}
\]
His total driving time was
\[
30+50=80\text{ minutes}
\]
The answer is not 50 minutes, since that is only the highway time.
\[
\boxed{80}
\]
ANSWER 2: C
Problem 3:
We are told that
\[
2^w\cdot 3^x\cdot 5^y\cdot 7^z=588
\]
Factor 588 into primes:
\[
588=2\cdot 294=2^2\cdot 147=2^2\cdot 3\cdot 49
\]
Thus,
\[
588=2^2\cdot 3^1\cdot 5^0\cdot 7^2
\]
So
\[
w=2,\qquad x=1,\qquad y=0,\qquad z=2
\]
Now calculate:
\[
2w+3x+5y+7z
\]
\[
=2(2)+3(1)+5(0)+7(2)
\]
\[
=4+3+0+14=21
\]
The factor \(5^0\) is important: since 588 has no factor of 5, \(y=0\), not 1.
\[
\boxed{21}
\]
ANSWER 3: A
Problem 4:
We compare all runners’ finishing times relative to Pedro.
- Nico finished 11 minutes behind Pedro.
- Olympia finished 3 minutes behind Pedro.
- Olympia finished 2 minutes ahead of Melina, so Melina finished 2 minutes behind Olympia.
- Olympia finished 6 minutes ahead of Luke, so Luke finished 6 minutes behind Olympia.
Let Pedro finish at time 0.
Then:
\[
\begin{array}{c|c}
\text{Runner} & \text{Minutes behind Pedro} \\
\hline
\text{Pedro} & 0\\
\text{Olympia} & 3\\
\text{Melina} & 3+2=5\\
\text{Luke} & 3+6=9\\
\text{Nico} & 11
\end{array}
\]
Therefore, the order is:
1. Pedro
2. Olympia
3. Melina
4. Luke
5. Nico
So Luke finished fourth.
\[
\boxed{\text{Luke}}
\]
ANSWER 4: A
Problem 5:
Walter is at school from 7:30 a.m. until 4:00 p.m.
That is:
\[
8\text{ hours }30\text{ minutes}=510\text{ minutes}
\]
His school-day activities take:
- 6 classes of 50 minutes each:
\[
6\cdot 50=300\text{ minutes}
\]
- Lunch:
\[
30\text{ minutes}
\]
- Additional school time:
\[
2\text{ hours}=120\text{ minutes}
\]
Total time not spent on the bus:
\[
300+30+120=450\text{ minutes}
\]
Therefore, bus time is
\[
510-450=60\text{ minutes}
\]
This includes both the ride to school and the ride home.
\[
\boxed{60}
\]
ANSWER 5: B
Problem 6:
Let the number of girls be \(g\).
There are two more boys than girls, so the number of boys is
\[
g+2
\]
Each boy receives as many jelly beans as there are boys, so the boys receive
\[
(g+2)(g+2)=(g+2)^2
\]
jelly beans altogether.
Each girl receives \(g\) jelly beans, so the girls receive
\[
g^2
\]
jelly beans altogether.
Mrs. Awesome gave away
\[
400-6=394
\]
jelly beans. Therefore,
\[
g^2+(g+2)^2=394
\]
Expand:
\[
g^2+g^2+4g+4=394
\]
\[
2g^2+4g-390=0
\]
Divide by 2:
\[
g^2+2g-195=0
\]
Factor:
\[
(g+15)(g-13)=0
\]
So
\[
g=13
\]
since a number of girls cannot be negative.
Thus boys:
\[
13+2=15
\]
Total students:
\[
13+15=28
\]
\[
\boxed{28}
\]
ANSWER 6: B
Problem 7:
During the first 30,000 miles, the car always uses 4 tires on the road.
So the total number of tire-miles used is
\[
4\cdot 30{,}000=120{,}000
\]
There are 5 tires total, and they were rotated so each tire was used equally.
Therefore, each tire was used
\[
\frac{120{,}000}{5}=24{,}000
\]
miles.
It is not 30,000 miles because only four of the five tires are being driven on at any one time.
\[
\boxed{24{,}000}
\]
ANSWER 7: C
Problem 8:
We need two-digit multiples of 7 whose digits add to 10.
The two-digit multiples of 7 are:
\[
14,21,28,35,42,49,56,63,70,77,84,91,98
\]
Check digit sums:
\[
28:\quad 2+8=10
\]
\[
91:\quad 9+1=10
\]
These are the only two.
Their sum is
\[
28+91=119
\]
\[
\boxed{119}
\]
ANSWER 8: A
Problem 9:
The volume of a cylinder is
\[
V=\pi r^2h
\]
For Alex’s can:
- Diameter \(=6\), so radius \(=3\)
- Height \(=12\)
\[
V_A=\pi(3)^2(12)=108\pi
\]
For Felicia’s can:
- Diameter \(=12\), so radius \(=6\)
- Height \(=6\)
\[
V_F=\pi(6)^2(6)=216\pi
\]
The ratio of Alex’s volume to Felicia’s volume is
\[
108\pi:216\pi
\]
Divide both parts by \(108\pi\):
\[
1:2
\]
Although Alex’s can is twice as tall, Felicia’s radius is twice as large, and radius is squared in the volume formula.
\[
\boxed{1:2}
\]
ANSWER 9: B
Problem 10:
We seek the smallest number greater than 2 that leaves remainder 2 when divided by 3, 4, 5, and 6.
If the number is \(n\), then \(n-2\) must be divisible by all of
\[
3,\ 4,\ 5,\ 6
\]
The least common multiple is
\[
\operatorname{lcm}(3,4,5,6)=60
\]
So the smallest possible value of \(n-2\) is 60:
\[
n-2=60
\]
\[
n=62
\]
The number 62 lies between 61 and 65.
Indeed:
\[
62\div 3,\ 62\div 4,\ 62\div 5,\ 62\div 6
\]
all leave remainder 2.
\[
\boxed{61\text{ and }65}
\]
ANSWER 10: D |
Walter catches the school bus at 7:30 a.m., has 6 classes that last 50 minutes each, has 30 minutes for lunch, and has 2 hours of additional time at school. He takes the bus home and arrives at 4:00 p.m. How many minutes has he spent on the bus?
| Model | Pick | ✓/✗ | Reasoning |
|---|---|---|---|
openrouter:meta/muse-spark-1.3 |
B | ✓ | showProblem 1: We are asked for the final price after a discount and then tax. Original price is 80 dollars. 25% off means pay 100% - 25% = 75% of original. Sale price = 0.75 × 80 = 60 dollars. Tempting mistake: subtract 25 dollars to get 55. No, 25% means percent, not dollars. Then 10% tax is added to the sale price, not the original price. Tax = 10% of 60 = 6 dollars. Total = 60 + 6 = 66 dollars. Equivalently 1.10 × 60 = 66. Check: A 45 is far too low. B 52 would be 35% off total. C 54 would be adding tax incorrectly. E 68 would be adding 10% of 80. ANSWER 1: D Problem 2: We need total time = time on coastal road + time on highway. Given time on coastal road = 30 minutes for 10 miles. Let coastal speed = v. Then v = 10 miles / 30 min. Highway speed is three times as fast: 3v. Highway distance is 50 miles. Time = distance / speed, so: Highway time = 50 / (3v). From coastal: 10 / v = 30, so 1/v = 3 min per mile. Thus highway time = 50 / 3 × (1/v) = 50/3 × 3 = 50 minutes. Total = 30 + 50 = 80 minutes. Alternative check: Highway is 5 times distance but 3 times speed, so takes 5/3 as long as coastal: 30 × 5/3 = 50. ANSWER 2: C Problem 3: We are told w,x,y,z are whole numbers, so 0,1,2,... And 2^w · 3^x · 5^y · 7^z = 588. Find 2w + 3x + 5y + 7z. Factor 588 into primes. 588 = 58.8 × 10, but do integer: 588 = 2 × 294 = 2 × 2 × 147 = 4 × 147. 147 = 3 × 49 = 3 × 7 × 7. So 588 = 2^2 × 3^1 × 5^0 × 7^2. By uniqueness of prime factorization, exponents must match: w = 2, x = 1, y = 0, z = 2. Note y=0 is allowed because whole numbers include 0, and 5^0 = 1. Now compute linear expression: 2w + 3x + 5y + 7z = 2×2 + 3×1 + 5×0 + 7×2 = 4 + 3 + 0 + 14 = 21. ANSWER 3: A Problem 4: Order the five finishers by time behind Pedro. Let Pedro's time be P. Nico finished 11 minutes behind Pedro: N = P+11. Olympia finished 3 minutes behind Pedro: O = P+3. Olympia finished 2 minutes ahead of Melina: So Melina is 2 minutes behind Olympia: M = O+2 = P+5. Olympia finished 6 minutes ahead of Luke: So Luke is 6 minutes behind Olympia: L = O+6 = P+9. Order by increasing time: Pedro at P+0 — 1st Olympia at P+3 — 2nd Melina at P+5 — 3rd Luke at P+9 — 4th Nico at P+11 — 5th So fourth is Luke. ANSWER 4: A Problem 5: Total elapsed time from boarding morning bus to arriving home. From 7:30 a.m. to 4:00 p.m. = 8.5 hours = 8×60 + 30 = 510 minutes. Time at school: 6 classes × 50 min = 300 min. Lunch 30 min. Additional 2 hours = 120 min. Total school = 300 + 30 + 120 = 450 min. Bus time (morning + afternoon) = total elapsed - school time = 510 - 450 = 60 minutes. Tempting error: miscount 7:30 to 4:00 as 8 hours. ANSWER 5: B Problem 6: Let g = number of girls. Then number of boys b = g+2. Each boy gets b beans, so boys total = b × b = b^2. Each girl gets g beans, so girls total = g × g = g^2. Beans used = 400 - 6 left = 394. So b^2 + g^2 = 394. Substitute: (g+2)^2 + g^2 = 394 g^2 + 4g + 4 + g^2 = 394 2g^2 + 4g - 390 = 0 Divide 2: g^2 + 2g - 195 = 0. Factor 195 = 13 × 15, differing by 2: (g+15)(g-13)=0. Positive solution g = 13. Then b = 15. Total students = 13+15 = 28. Check: 15^2+13^2 =225+169=394 correct. ANSWER 6: B Problem 7: The car travels 30,000 miles. At any moment exactly 4 tires are on the road carrying it. Total tire-miles delivered = 4 tires × 30,000 miles = 120,000 tire-miles. This wear is shared equally among 5 tires by rotation. Per tire = 120,000 / 5 = 24,000 miles. Tempting wrong: 30,000/5 = 6,000 ignores that 4 tires are used at once. 30,000 would mean no rotation. ANSWER 7: C Problem 8: List two-digit multiples of 7: 14,21,28,35,42,49,56,63,70,77,84,91,98. Compute digit sums: 1+4=5, 2+1=3, 2+8=10, 3+5=8, 4+2=6, 4+9=13, 5+6=11, 6+3=9, 7+0=7, 7+7=14, 8+4=12, 9+1=10, 9+8=17. Only two have sum 10: 28 and 91. Their sum = 28+91 = 119. ANSWER 8: A Problem 9: Volume of cylinder = π r^2 h, where r = diameter/2. Alex: diameter 6, so r=3. height 12. V_A = π × 3^2 × 12 = π × 9 × 12 = 108π. Felicia: diameter 12, so r=6. height 6. V_F = π × 6^2 × 6 = π × 36 × 6 = 216π. Ratio V_A : V_F = 108π : 216π = 108:216 = 1:2. Note volume scales with square of radius, so doubling diameter quadruples base area, outweighing halving height. ANSWER 9: B Problem 10: We need N > 2 with N ≡ 2 mod 3, mod 4, mod 5, mod 6. So N-2 is divisible by each of 3,4,5,6. N-2 must be a common multiple of 3,4,5,6. LCM(3,4,5,6): 4=2^2, 6=2×3, so LCM = 2^2 × 3 × 5 = 60. Positive multiples: 60,120,... N=2 gives N-2=0 which works but is excluded by >2. Next smallest is N-2 = 60, so N = 62. 62 is between 61 and 65. Check: 62 ÷ 3 =20 rem 2, ÷4=15 rem 2, etc. ANSWER 10: D |
openrouter:google/gemini-3.8-flash |
B | ✓ | showProblem 1:
**Restatement and Setup:**
We are given an item with an original price of $\$80$. It is discounted by $25\%$, and then a $10\%$ sales tax is applied to this discounted sale price. We need to find the final total selling price.
**Step-by-step computation:**
1. Calculate the discount:
$$\text{Discount} = 25\% \text{ of } \$80 = 0.25 \times 80 = \$20$$
2. Calculate the sale price:
$$\text{Sale Price} = \$80 - \$20 = \$60$$
*(Alternatively, the sale price is $75\%$ of $\$80$: $0.75 \times 80 = \$60$.)*
3. Calculate the tax on the sale price:
$$\text{Tax} = 10\% \text{ of } \$60 = 0.10 \times 60 = \$6$$
4. Calculate the total price:
$$\text{Total Price} = \$60 + \$6 = \$66$$
**Ruling out wrong choices:**
- Choice A ($\$45$) results from incorrectly subtracting both $25\%$ and $10\%$ from the original price, or similar errors.
- Choice B ($\$52$) and Choice C ($\$54$) are too low.
- Choice E ($\$68$) might occur if the tax were incorrectly computed on the original $\$80$ price ($80 \times 0.10 = \$8$) and added to $\$60$.
ANSWER 1: D
---
Problem 2:
**Restatement and Setup:**
Anh drives on two segments:
- Coastal access road: distance $d_c = 10$ miles, time $t_c = 30$ minutes.
- Highway: distance $d_h = 50$ miles.
He drives three times as fast on the highway as on the coastal access road ($v_h = 3 v_c$). We need to find the total time in minutes for the entire trip.
**Step-by-step computation:**
1. Find the speed on the coastal road:
Anh drives $10$ miles in $30$ minutes ($0.5$ hours).
$$v_c = \frac{10\text{ miles}}{0.5\text{ hours}} = 20\text{ mph}$$
2. Find the speed on the highway:
$$v_h = 3 \times v_c = 3 \times 20\text{ mph} = 60\text{ mph} = 1\text{ mile per minute}$$
3. Find the time spent on the highway:
$$t_h = \frac{50\text{ miles}}{1\text{ mile per minute}} = 50\text{ minutes}$$
4. Find the total trip time:
$$\text{Total time} = t_c + t_h = 30\text{ minutes} + 50\text{ minutes} = 80\text{ minutes}$$
**Ruling out wrong choices:**
- Choice A ($50$) is just the time on the highway.
- Choices B ($70$), D ($90$), and E ($100$) arise from miscalculating the highway speed ratio or mixing up minutes and hours.
ANSWER 2: C
---
Problem 3:
**Restatement and Setup:**
Given whole numbers (non-negative integers) $w, x, y, z$ such that:
$$2^w \cdot 3^x \cdot 5^y \cdot 7^z = 588$$
We need to find the value of $2w + 3x + 5y + 7z$.
**Step-by-step computation:**
1. Find the prime factorization of $588$:
$$588 = 2 \times 294 = 2 \times 2 \times 147 = 4 \times 3 \times 49 = 2^2 \times 3^1 \times 7^2$$
2. Matching the prime factors with $2^w \cdot 3^x \cdot 5^y \cdot 7^z$:
- $w = 2$
- $x = 1$
- $y = 0$ (since $5$ is not a factor of $588$)
- $z = 2$
3. Compute the required expression $2w + 3x + 5y + 7z$:
$$2(2) + 3(1) + 5(0) + 7(2) = 4 + 3 + 0 + 14 = 21$$
**Ruling out wrong choices:**
- If one mistakenly sets $y=1$, the sum would be $21 + 5 = 26$ (close to 25 or 27).
- Choices B, C, D, and E do not match the evaluated sum of $21$.
ANSWER 3: A
---
Problem 4:
**Restatement and Setup:**
Five runners (Luke, Melina, Nico, Olympia, Pedro) finished a race. We are given relative finish times:
- Nico finished $11$ minutes behind Pedro.
- Olympia finished $3$ minutes behind Pedro.
- Olympia finished $2$ minutes ahead of Melina.
- Olympia finished $6$ minutes ahead of Luke.
We need to determine who finished in fourth place.
**Step-by-step computation:**
Let Pedro's finish time be $t=0$ minutes (the earliest/winner).
- Pedro finishes at $0$ minutes.
- Olympia finished $3$ minutes behind Pedro $\implies$ Olympia finishes at $0 + 3 = 3$ minutes.
- Olympia finished $2$ minutes ahead of Melina $\implies$ Melina finishes $2$ minutes after Olympia $\implies 3 + 2 = 5$ minutes.
- Olympia finished $6$ minutes ahead of Luke $\implies$ Luke finishes $6$ minutes after Olympia $\implies 3 + 6 = 9$ minutes.
- Nico finished $11$ minutes behind Pedro $\implies$ Nico finishes at $0 + 11 = 11$ minutes.
Listing the runners in order of finish:
1. Pedro ($0$ min)
2. Olympia ($3$ min)
3. Melina ($5$ min)
4. Luke ($9$ min)
5. Nico ($11$ min)
Thus, Luke finished fourth.
**Ruling out wrong choices:**
- Pedro was 1st, Olympia was 2nd, Melina was 3rd, and Nico was 5th (last).
ANSWER 4: A
---
Problem 5:
**Restatement and Setup:**
Walter boards the bus at 7:30 a.m. and arrives home from the bus at 4:00 p.m.
During the day, he spends time on the bus (both ways) and at school.
School activities consist of:
- $6$ classes of $50$ minutes each
- $30$ minutes for lunch
- $2$ hours of additional time
We need to find the total time Walter spent on the bus.
**Step-by-step computation:**
1. Calculate total elapsed time between leaving home and returning:
- From 7:30 a.m. to 12:00 p.m. is $4$ hours and $30$ minutes ($4.5$ hours).
- From 12:00 p.m. to 4:00 p.m. is $4$ hours.
- Total elapsed time = $8$ hours and $30$ minutes $= 8 \times 60 + 30 = 510$ minutes.
2. Calculate total time spent on school activities:
- Classes: $6 \times 50\text{ minutes} = 300\text{ minutes}$
- Lunch: $30\text{ minutes}$
- Additional time: $2\text{ hours} = 120\text{ minutes}$
- Total school time $= 300 + 30 + 120 = 450\text{ minutes}$.
3. Calculate time spent on the bus:
$$\text{Bus time} = \text{Total time} - \text{School time} = 510 - 450 = 60\text{ minutes}$$
**Ruling out wrong choices:**
- 30 minutes assumes only a one-way trip or forgets additional school time.
- 75, 90, 120 minutes result from miscounting the elapsed time or forgetting the 30-minute lunch.
ANSWER 5: B
---
Problem 6:
**Restatement and Setup:**
Let $b$ be the number of boys and $g$ be the number of girls.
- Each boy receives $b$ jelly beans (total $b^2$).
- Each girl receives $g$ jelly beans (total $g^2$).
- Total jelly beans distributed: $400 - 6 = 394$.
- There are two more boys than girls: $b = g + 2$.
We need to find the total number of students in the class, which is $b + g$.
**Step-by-step com |
openrouter:~z-ai/glm-latest |
B | ✓ | show# Problem 1: **What is asked:** Find the final price after a 25% discount on $80, followed by 10% tax on the *sale price*. **Step 1 — Compute the sale price (25% off):** Discount = 25% of 80 = 0.25 × 80 = $20. Sale price = 80 − 20 = **$60**. **Step 2 — Add 10% tax to the sale price:** Tax = 10% of 60 = $6. Total = 60 + 6 = **$66**. **Rule out wrong answers:** - $52 (B) comes from wrongly taking 10% off the *original* price (60 − 8), but tax is added, not discounted. - $54 (C) comes from adding discounts: 80 × 0.75 × 0.9 — but tax increases the price. - The correct sequence is 80 → 60 → 66. ANSWER 1: D # Problem 2: **What is asked:** Find the total driving time in minutes. **Step 1 — Coastal road speed:** Anh drove 10 miles in 30 minutes (= 0.5 hour). Speed = 10 ÷ 0.5 = **20 mph**. **Step 2 — Highway speed:** He drove 3 times as fast: 3 × 20 = **60 mph**. **Step 3 — Highway time:** Time = distance ÷ speed = 50 ÷ 60 = 5/6 hour = **50 minutes**. **Step 4 — Total time:** 30 + 50 = **80 minutes**. **Rule out wrong answers:** - 90 (D) would result from wrongly assuming equal speeds (30 min + 60 min); but the highway was faster, so its time is *less* than 60 minutes. Only 80 fits. ANSWER 2: C # Problem 3: **What is asked:** Given 2^w · 3^x · 5^y · 7^z = 588, find 2w + 3x + 5y + 7z. **Step 1 — Factor 588:** 588 = 4 × 147 = 4 × 3 × 49 = 2² × 3 × 7². **Step 2 — Read off exponents:** 588 = 2² · 3¹ · 5⁰ · 7², so w = 2, x = 1, y = 0, z = 2. **Step 3 — Compute the expression:** 2w + 3x + 5y + 7z = 2(2) + 3(1) + 5(0) + 7(2) = 4 + 3 + 0 + 14 = **21**. **Rule out wrong answers:** 35 (D) or 56 (E) would come from confusing the coefficients 2,3,5,7 with the bases; note 588 is not divisible by 5, forcing y = 0. ANSWER 3: A # Problem 4: **What is asked:** Determine which runner finished fourth (in order of finishing time). **Step 1 — Set Pedro's time as P (a reference).** Then: - Nico finished 11 minutes behind Pedro: Nico = P + 11. - Olympia finished 3 minutes behind Pedro: Olympia = P + 3. - Olympia finished 2 minutes ahead of Melina, so Melina = P + 3 + 2 = P + 5. - Olympia finished 6 minutes ahead of Luke, so Luke = P + 3 + 6 = P + 9. **Step 2 — Order from fastest to slowest:** Pedro (P), Olympia (P+3), Melina (P+5), Luke (P+9), Nico (P+11). **Step 3 — Fourth place** is **Luke**. **Rule out wrong answers:** Nico (C) is last (5th), Pedro (E) is first; a common error is swapping Luke and Melina — but Luke = P+9 is behind Melina = P+5. ANSWER 4: A # Problem 5: **What is asked:** Total time Walter spent on the bus (both ways). **Step 1 — Total elapsed time from 7:30 a.m. to 4:00 p.m.:** That is 8 hours 30 minutes = 510 minutes. **Step 2 — Time accounted for at school:** - Classes: 6 × 50 = 300 minutes - Lunch: 30 minutes - Additional time: 2 hours = 120 minutes - Total school time: 300 + 30 + 120 = 450 minutes. **Step 3 — Bus time:** 510 − 450 = **60 minutes**. **Rule out wrong answers:** 90 (D) would ignore lunch or additional time; 30 (A) would count only one bus ride — but the round trip must be 60 minutes total. ANSWER 5: B # Problem 6: **What is asked:** Find the total number of students. **Step 1 — Set up equations.** Let g = number of girls, b = number of boys. Each boy gets b beans (b boys), each girl gets g beans (g girls): b² + g² = 400 − 6 = 394, and b = g + 2. **Step 2 — Substitute and solve:** (g+2)² + g² = 394 g² + 4g + 4 + g² = 394 2g² + 4g − 390 = 0 g² + 2g − 195 = 0 (g + 15)(g − 13) = 0 → g = 13 (reject −15). **Step 3 — Find the total:** Boys: b = 13 + 2 = 15. Total students = 15 + 13 = **28**. **Check:** 15² + 13² = 225 + 169 = 394 = 400 − 6. ✓ ANSWER 6: B # Problem 7: **What is asked:** Miles each of the 5 tires was used over 30,000 miles. **Step 1 — Total tire-miles used:** At any moment the car uses 4 tires. Over 30,000 miles, total tire-miles = 4 × 30,000 = 120,000. **Step 2 — Split equally among 5 tires:** 120,000 ÷ 5 = **24,000 miles** each. **Rule out wrong answers:** 30,000 (D) is wrong because no single tire can be used the whole time when 5 tires share the work; 6,000 (A) and 7,500 (B) wrongly divide by the wrong quantity (e.g., 30,000 ÷ 5 or ÷ 4). ANSWER 7: C # Problem 8: **What is asked:** Sum of the two two-digit multiples of 7 whose digits sum to 10. **Step 1 — List two-digit multiples of 7 and digit sums:** 14 (5), 21 (3), **28 (10)** ✓, 35 (8), 42 (6), 49 (13), 56 (11), 63 (9), 70 (7), 77 (14), 84 (12), **91 (10)** ✓, 98 (17). **Step 2 — Identify the two qualifying numbers:** 28 and 91. **Step 3 — Sum:** 28 + 91 = **119**. **Rule out wrong answers:** 126 (B) is 63 + 63 — impossible since numbers are distinct; 140 (D) might come from 28 + 112 (but 112 is three digits). ANSWER 8: A # Problem 9: **What is asked:** Ratio of Alex's can volume to Felicia's can volume. **Step 1 — Volume formula:** V = πr²h. **Step 2 — Alex's can:** diameter 6 → radius 3; height 12. V_A = π(3)²(12) = 108π. **Step 3 — Felicia's can:** diameter 12 → radius 6; height 6. V_F = π(6)²(6) = 216π. **Step 4 — Ratio:** V_A : V_F = 108π : 216π = **1 : 2**. **Rule out wrong answers:** 1:1 (C) is the tempting "swapped dimensions" intuition, but volume depends on the *square* of the radius, so doubling the radius quadruples that factor while halving the height only halves — net effect is Felicia's can is twice as big. ANSWER 9: B # Problem 10: **What is asked:** Find the smallest number > 2 that leaves remainder 2 when divided by 3, 4, 5, and 6, and identify the interval containing it. **Step 1 — Interpret the condition:** N − 2 must be divisible by 3, 4, 5, and 6, i.e., N − 2 is a multiple of LCM(3, 4, 5, 6). **Step 2 — Compute the LCM:** LCM(3,4,5,6) = 60 (since 60 is divisible by 3, 4, 5, and 6). **Step 3 — Candidates:** N = 60k + 2 for whole numbers k: N = 2, 62, 122, ... The smallest *greater than 2* is **62**. **Step 4 — Locate 62:** It lies between **61 and 65**. **Rule out wrong answers:** 42 + 2 = 44 is a common error (using 42, the LCM of only |
openrouter:qwen/qwen3.8-27b |
B | ✓ | showProblem 1:
The dress is originally priced at \$80. A 25% discount means the sale price is
\[
80(1-0.25)=80(0.75)=60.
\]
Then 10% tax is added to the sale price:
\[
60(1+0.10)=60(1.10)=66.
\]
So the total selling price is \$66.
ANSWER 1: D
Problem 2:
Anh drove 10 miles on the coastal road in 30 minutes, so his coastal-road speed was
\[
\frac{10\text{ miles}}{30\text{ minutes}}.
\]
He drove three times as fast on the highway. Therefore, for the same distance, the highway time would be one-third as long.
For 50 miles on the highway, if he had driven at coastal-road speed, it would take
\[
30 \times \frac{50}{10}=150
\]
minutes. But because he drove three times as fast on the highway, the actual highway time is
\[
\frac{150}{3}=50
\]
minutes.
The coastal road took 30 minutes, so the total trip time was
\[
30+50=80
\]
minutes.
ANSWER 2: C
Problem 3:
The equation should be read as
\[
2^w \cdot 3^x \cdot 5^y \cdot 7^z = 588.
\]
Factor 588:
\[
588=2\cdot 294=2^2\cdot 147=2^2\cdot 3\cdot 49=2^2\cdot 3^1\cdot 7^2.
\]
There is no factor of 5, so \(y=0\). Comparing prime exponents gives
\[
w=2,\qquad x=1,\qquad y=0,\qquad z=2.
\]
Now compute
\[
2w+3x+5y+7z=2(2)+3(1)+5(0)+7(2).
\]
\[
=4+3+0+14=21.
\]
ANSWER 3: A
Problem 4:
Let Pedro’s finishing time be \(P\). In a race, a smaller time means finishing earlier.
- Nico finished 11 minutes behind Pedro, so Nico’s time is
\[
P+11.
\]
- Olympia finished 3 minutes behind Pedro, so Olympia’s time is
\[
P+3.
\]
- Olympia finished 2 minutes ahead of Melina, so Melina’s time is
\[
(P+3)+2=P+5.
\]
- Olympia finished 6 minutes ahead of Luke, so Luke’s time is
\[
(P+3)+6=P+9.
\]
Now order the runners from first to last by increasing time:
\[
P,\quad P+3,\quad P+5,\quad P+9,\quad P+11.
\]
That is:
1. Pedro
2. Olympia
3. Melina
4. Luke
5. Nico
So the fourth runner was Luke.
ANSWER 4: A
Problem 5:
From 7:30 a.m. to 4:00 p.m. is 8 hours and 30 minutes:
\[
8(60)+30=480+30=510
\]
minutes.
Walter’s time in school not spent on the bus is:
- 6 classes of 50 minutes each:
\[
6(50)=300
\]
minutes;
- lunch: 30 minutes;
- additional time: 2 hours = 120 minutes.
Total non-bus time:
\[
300+30+120=450
\]
minutes.
So his total bus time was
\[
510-450=60
\]
minutes.
ANSWER 5: B
Problem 6:
Let the number of girls be \(g\). Since there were two more boys than girls, the number of boys is
\[
g+2.
\]
Mrs. Awesome gave each boy as many jelly beans as there were boys, so the boys received
\[
(g+2)^2
\]
jelly beans total. Each girl received as many as there were girls, so the girls received
\[
g^2
\]
jelly beans total.
She had 400 jelly beans and 6 left, so she gave away
\[
400-6=394.
\]
Thus,
\[
(g+2)^2+g^2=394.
\]
Expand:
\[
g^2+4g+4+g^2=394
\]
\[
2g^2+4g+4=394
\]
\[
2g^2+4g-390=0
\]
Divide by 2:
\[
g^2+2g-195=0.
\]
Factor:
\[
(g+15)(g-13)=0.
\]
Since \(g\) must be positive,
\[
g=13.
\]
Then the number of boys is
\[
13+2=15.
\]
The total number of students is
\[
13+15=28.
\]
ANSWER 6: B
Problem 7:
During the first 30,000 miles, the car was always using 4 tires at once. Therefore, the total “tire-miles” used is
\[
4 \times 30{,}000=120{,}000.
\]
There are 5 tires total, and they were all used the same number of miles. So each tire was used for
\[
\frac{120{,}000}{5}=24{,}000
\]
miles.
ANSWER 7: C
Problem 8:
We need two-digit multiples of 7 whose digits sum to 10.
The two-digit multiples of 7 are:
\[
14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84, 91, 98.
\]
Check digit sums:
\[
14: 1+4=5
\]
\[
21: 2+1=3
\]
\[
28: 2+8=10
\]
\[
35: 3+5=8
\]
\[
42: 4+2=6
\]
\[
49: 4+9=13
\]
\[
56: 5+6=11
\]
\[
63: 6+3=9
\]
\[
70: 7+0=7
\]
\[
77: 7+7=14
\]
\[
84: 8+4=12
\]
\[
91: 9+1=10
\]
\[
98: 9+8=17
\]
The only two are 28 and 91. Their sum is
\[
28+91=119.
\]
ANSWER 8: A
Problem 9:
The volume of a cylinder is
\[
V=\pi r^2h.
\]
Alex’s cans have diameter 6 cm, so radius 3 cm, and height 12 cm:
\[
V_A=\pi(3^2)(12)=\pi(9)(12)=108\pi.
\]
Felicia’s cans have diameter 12 cm, so radius 6 cm, and height 6 cm:
\[
V_F=\pi(6^2)(6)=\pi(36)(6)=216\pi.
\]
The ratio of Alex’s can volume to Felicia’s can volume is
\[
108\pi:216\pi=108:216=1:2.
\]
ANSWER 9: B
Problem 10:
Let the number be \(N\). It leaves a remainder of 2 when divided by 3, 4, 5, and 6, so
\[
N-2
\]
is divisible by 3, 4, 5, and 6. Therefore, \(N-2\) must be a multiple of the least common multiple of 3, 4, 5, and 6.
Find the LCM:
\[
\operatorname{lcm}(3,4,5,6)=60.
\]
So
\[
N-2=60k
\]
for some positive integer \(k\), because we need \(N>2\).
The smallest possible value is when \(k=1\):
\[
N-2=60
\]
\[
N=62.
\]
This lies between 61 and 65.
ANSWER 10: D |
openrouter:anthropic/claude-opus-5 |
B | ✓ | showProblem 1: Sale price: 25% off means you pay 75%: 80 × 0.75 = 60 dollars. Add 10% tax: 60 × 1.10 = 66 dollars. (Choice C, 54, would come from subtracting 10%; choice D is correct. Note taking 25% off then adding 10% doesn't return to 80.) ANSWER 1: D Problem 2: Coastal road: 10 miles in 30 minutes, so 3 minutes per mile. Highway speed is 3 times as fast, so 1 minute per mile. Highway time: 50 miles × 1 minute/mile = 50 minutes. Total: 50 + 30 = 80 minutes. (Choice A forgets the coastal 30 minutes; choice D would come from using 3 min/mile on the highway incorrectly.) ANSWER 2: C Problem 3: The equation is 2^w · 3^x · 5^y · 7^z = 588. Factor 588 = 4 · 147 = 2² · 3 · 7². So w = 2, x = 1, y = 0, z = 2. Then 2w + 3x + 5y + 7z = 2(2) + 3(1) + 5(0) + 7(2) = 4 + 3 + 0 + 14 = 21. ANSWER 3: A Problem 4: Let Pedro's time be 0 (he's a reference). - Nico = +11 - Olympia = +3 (3 min behind Pedro) - Melina = Olympia + 2 = +5 - Luke = Olympia + 6 = +9 Order from first: Pedro (0), Olympia (3), Melina (5), Luke (9), Nico (11). Fourth place is Luke. ANSWER 4: A Problem 5: Total time away: 7:30 a.m. to 4:00 p.m. = 8 hours 30 minutes = 510 minutes. Time at school: classes 6 × 50 = 300, lunch 30, extra 2 hours = 120; total 450 minutes. Bus time = 510 − 450 = 60 minutes (both trips combined). ANSWER 5: B Problem 6: Let g = number of girls, b = g + 2 boys. Jelly beans used: b² + g² = 400 − 6 = 394. (g + 2)² + g² = 394 → 2g² + 4g + 4 = 394 → g² + 2g − 195 = 0 → (g + 15)(g − 13) = 0 → g = 13. So girls = 13, boys = 15; check 169 + 225 = 394 ✓. Total students = 28. ANSWER 6: B Problem 7: Four tires are on the road at any time, so total tire-miles = 4 × 30,000 = 120,000. Shared equally among 5 tires: 120,000 ÷ 5 = 24,000 miles each. (30,000 would be if no rotation; 6,000 is the rest time per tire, not use.) ANSWER 7: C Problem 8: Two-digit multiples of 7: 14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84, 91, 98. Digit sums: 5, 3, 10, 8, 6, 13, 11, 9, 7, 14, 12, 10, 17. Digit sum 10 occurs for 28 and 91. Sum: 28 + 91 = 119. ANSWER 8: A Problem 9: Alex: diameter 6 → radius 3, height 12: V = π(3²)(12) = 108π. Felicia: diameter 12 → radius 6, height 6: V = π(6²)(6) = 216π. Ratio = 108π : 216π = 1 : 2. (Doubling the radius quadruples volume, while halving height only halves it, so Felicia's is twice as big — not equal.) ANSWER 9: B Problem 10: A number leaving remainder 2 when divided by 3, 4, 5, and 6 must be 2 more than a common multiple of 3, 4, 5, 6. LCM(3, 4, 5, 6) = 60, so the smallest such number greater than 2 is 60 + 2 = 62. 62 lies between 61 and 65. ANSWER 10: D |
openrouter:openai/gpt-5.6-terra-pro |
B | ✓ | showProblem 1:
The dress was originally priced at \$80.
A 25% discount means the sale price is \(75\%\) of the original price:
\[
80 \times 0.75=60
\]
Then 10% tax is added:
\[
10\% \text{ of } 60 = 6
\]
So the total price is
\[
60+6=66
\]
A common mistake is to subtract 25% and add 10% of the original \$80, but the tax is added to the reduced sale price, not the original price.
\[
\boxed{66}
\]
ANSWER 1: D
Problem 2:
Anh drove 10 miles on the coastal road in 30 minutes.
Since 30 minutes is \(\frac12\) hour, his coastal-road speed was
\[
\frac{10\text{ miles}}{\frac12\text{ hour}}=20\text{ miles per hour}
\]
He drove three times as fast on the highway:
\[
3(20)=60\text{ miles per hour}
\]
The highway trip was 50 miles, so the highway driving time was
\[
\frac{50}{60}\text{ hour}=\frac56\text{ hour}
\]
Convert \(\frac56\) hour to minutes:
\[
\frac56\cdot 60=50\text{ minutes}
\]
His total driving time was
\[
30+50=80\text{ minutes}
\]
The answer is not 50 minutes, since that is only the highway time.
\[
\boxed{80}
\]
ANSWER 2: C
Problem 3:
We are told that
\[
2^w\cdot 3^x\cdot 5^y\cdot 7^z=588
\]
Factor 588 into primes:
\[
588=2\cdot 294=2^2\cdot 147=2^2\cdot 3\cdot 49
\]
Thus,
\[
588=2^2\cdot 3^1\cdot 5^0\cdot 7^2
\]
So
\[
w=2,\qquad x=1,\qquad y=0,\qquad z=2
\]
Now calculate:
\[
2w+3x+5y+7z
\]
\[
=2(2)+3(1)+5(0)+7(2)
\]
\[
=4+3+0+14=21
\]
The factor \(5^0\) is important: since 588 has no factor of 5, \(y=0\), not 1.
\[
\boxed{21}
\]
ANSWER 3: A
Problem 4:
We compare all runners’ finishing times relative to Pedro.
- Nico finished 11 minutes behind Pedro.
- Olympia finished 3 minutes behind Pedro.
- Olympia finished 2 minutes ahead of Melina, so Melina finished 2 minutes behind Olympia.
- Olympia finished 6 minutes ahead of Luke, so Luke finished 6 minutes behind Olympia.
Let Pedro finish at time 0.
Then:
\[
\begin{array}{c|c}
\text{Runner} & \text{Minutes behind Pedro} \\
\hline
\text{Pedro} & 0\\
\text{Olympia} & 3\\
\text{Melina} & 3+2=5\\
\text{Luke} & 3+6=9\\
\text{Nico} & 11
\end{array}
\]
Therefore, the order is:
1. Pedro
2. Olympia
3. Melina
4. Luke
5. Nico
So Luke finished fourth.
\[
\boxed{\text{Luke}}
\]
ANSWER 4: A
Problem 5:
Walter is at school from 7:30 a.m. until 4:00 p.m.
That is:
\[
8\text{ hours }30\text{ minutes}=510\text{ minutes}
\]
His school-day activities take:
- 6 classes of 50 minutes each:
\[
6\cdot 50=300\text{ minutes}
\]
- Lunch:
\[
30\text{ minutes}
\]
- Additional school time:
\[
2\text{ hours}=120\text{ minutes}
\]
Total time not spent on the bus:
\[
300+30+120=450\text{ minutes}
\]
Therefore, bus time is
\[
510-450=60\text{ minutes}
\]
This includes both the ride to school and the ride home.
\[
\boxed{60}
\]
ANSWER 5: B
Problem 6:
Let the number of girls be \(g\).
There are two more boys than girls, so the number of boys is
\[
g+2
\]
Each boy receives as many jelly beans as there are boys, so the boys receive
\[
(g+2)(g+2)=(g+2)^2
\]
jelly beans altogether.
Each girl receives \(g\) jelly beans, so the girls receive
\[
g^2
\]
jelly beans altogether.
Mrs. Awesome gave away
\[
400-6=394
\]
jelly beans. Therefore,
\[
g^2+(g+2)^2=394
\]
Expand:
\[
g^2+g^2+4g+4=394
\]
\[
2g^2+4g-390=0
\]
Divide by 2:
\[
g^2+2g-195=0
\]
Factor:
\[
(g+15)(g-13)=0
\]
So
\[
g=13
\]
since a number of girls cannot be negative.
Thus boys:
\[
13+2=15
\]
Total students:
\[
13+15=28
\]
\[
\boxed{28}
\]
ANSWER 6: B
Problem 7:
During the first 30,000 miles, the car always uses 4 tires on the road.
So the total number of tire-miles used is
\[
4\cdot 30{,}000=120{,}000
\]
There are 5 tires total, and they were rotated so each tire was used equally.
Therefore, each tire was used
\[
\frac{120{,}000}{5}=24{,}000
\]
miles.
It is not 30,000 miles because only four of the five tires are being driven on at any one time.
\[
\boxed{24{,}000}
\]
ANSWER 7: C
Problem 8:
We need two-digit multiples of 7 whose digits add to 10.
The two-digit multiples of 7 are:
\[
14,21,28,35,42,49,56,63,70,77,84,91,98
\]
Check digit sums:
\[
28:\quad 2+8=10
\]
\[
91:\quad 9+1=10
\]
These are the only two.
Their sum is
\[
28+91=119
\]
\[
\boxed{119}
\]
ANSWER 8: A
Problem 9:
The volume of a cylinder is
\[
V=\pi r^2h
\]
For Alex’s can:
- Diameter \(=6\), so radius \(=3\)
- Height \(=12\)
\[
V_A=\pi(3)^2(12)=108\pi
\]
For Felicia’s can:
- Diameter \(=12\), so radius \(=6\)
- Height \(=6\)
\[
V_F=\pi(6)^2(6)=216\pi
\]
The ratio of Alex’s volume to Felicia’s volume is
\[
108\pi:216\pi
\]
Divide both parts by \(108\pi\):
\[
1:2
\]
Although Alex’s can is twice as tall, Felicia’s radius is twice as large, and radius is squared in the volume formula.
\[
\boxed{1:2}
\]
ANSWER 9: B
Problem 10:
We seek the smallest number greater than 2 that leaves remainder 2 when divided by 3, 4, 5, and 6.
If the number is \(n\), then \(n-2\) must be divisible by all of
\[
3,\ 4,\ 5,\ 6
\]
The least common multiple is
\[
\operatorname{lcm}(3,4,5,6)=60
\]
So the smallest possible value of \(n-2\) is 60:
\[
n-2=60
\]
\[
n=62
\]
The number 62 lies between 61 and 65.
Indeed:
\[
62\div 3,\ 62\div 4,\ 62\div 5,\ 62\div 6
\]
all leave remainder 2.
\[
\boxed{61\text{ and }65}
\]
ANSWER 10: D |
On the last day of school, Mrs. Awesome gave jelly beans to her class. She gave each boy as many jelly beans as there were boys in the class. She gave each girl as many jelly beans as there were girls in the class. She brought 400 jelly beans, and when she finished, she had six jelly beans left. There were two more boys than girls in her class. How many students were in her class?
| Model | Pick | ✓/✗ | Reasoning |
|---|---|---|---|
openrouter:meta/muse-spark-1.3 |
B | ✓ | showProblem 1: We are asked for the final price after a discount and then tax. Original price is 80 dollars. 25% off means pay 100% - 25% = 75% of original. Sale price = 0.75 × 80 = 60 dollars. Tempting mistake: subtract 25 dollars to get 55. No, 25% means percent, not dollars. Then 10% tax is added to the sale price, not the original price. Tax = 10% of 60 = 6 dollars. Total = 60 + 6 = 66 dollars. Equivalently 1.10 × 60 = 66. Check: A 45 is far too low. B 52 would be 35% off total. C 54 would be adding tax incorrectly. E 68 would be adding 10% of 80. ANSWER 1: D Problem 2: We need total time = time on coastal road + time on highway. Given time on coastal road = 30 minutes for 10 miles. Let coastal speed = v. Then v = 10 miles / 30 min. Highway speed is three times as fast: 3v. Highway distance is 50 miles. Time = distance / speed, so: Highway time = 50 / (3v). From coastal: 10 / v = 30, so 1/v = 3 min per mile. Thus highway time = 50 / 3 × (1/v) = 50/3 × 3 = 50 minutes. Total = 30 + 50 = 80 minutes. Alternative check: Highway is 5 times distance but 3 times speed, so takes 5/3 as long as coastal: 30 × 5/3 = 50. ANSWER 2: C Problem 3: We are told w,x,y,z are whole numbers, so 0,1,2,... And 2^w · 3^x · 5^y · 7^z = 588. Find 2w + 3x + 5y + 7z. Factor 588 into primes. 588 = 58.8 × 10, but do integer: 588 = 2 × 294 = 2 × 2 × 147 = 4 × 147. 147 = 3 × 49 = 3 × 7 × 7. So 588 = 2^2 × 3^1 × 5^0 × 7^2. By uniqueness of prime factorization, exponents must match: w = 2, x = 1, y = 0, z = 2. Note y=0 is allowed because whole numbers include 0, and 5^0 = 1. Now compute linear expression: 2w + 3x + 5y + 7z = 2×2 + 3×1 + 5×0 + 7×2 = 4 + 3 + 0 + 14 = 21. ANSWER 3: A Problem 4: Order the five finishers by time behind Pedro. Let Pedro's time be P. Nico finished 11 minutes behind Pedro: N = P+11. Olympia finished 3 minutes behind Pedro: O = P+3. Olympia finished 2 minutes ahead of Melina: So Melina is 2 minutes behind Olympia: M = O+2 = P+5. Olympia finished 6 minutes ahead of Luke: So Luke is 6 minutes behind Olympia: L = O+6 = P+9. Order by increasing time: Pedro at P+0 — 1st Olympia at P+3 — 2nd Melina at P+5 — 3rd Luke at P+9 — 4th Nico at P+11 — 5th So fourth is Luke. ANSWER 4: A Problem 5: Total elapsed time from boarding morning bus to arriving home. From 7:30 a.m. to 4:00 p.m. = 8.5 hours = 8×60 + 30 = 510 minutes. Time at school: 6 classes × 50 min = 300 min. Lunch 30 min. Additional 2 hours = 120 min. Total school = 300 + 30 + 120 = 450 min. Bus time (morning + afternoon) = total elapsed - school time = 510 - 450 = 60 minutes. Tempting error: miscount 7:30 to 4:00 as 8 hours. ANSWER 5: B Problem 6: Let g = number of girls. Then number of boys b = g+2. Each boy gets b beans, so boys total = b × b = b^2. Each girl gets g beans, so girls total = g × g = g^2. Beans used = 400 - 6 left = 394. So b^2 + g^2 = 394. Substitute: (g+2)^2 + g^2 = 394 g^2 + 4g + 4 + g^2 = 394 2g^2 + 4g - 390 = 0 Divide 2: g^2 + 2g - 195 = 0. Factor 195 = 13 × 15, differing by 2: (g+15)(g-13)=0. Positive solution g = 13. Then b = 15. Total students = 13+15 = 28. Check: 15^2+13^2 =225+169=394 correct. ANSWER 6: B Problem 7: The car travels 30,000 miles. At any moment exactly 4 tires are on the road carrying it. Total tire-miles delivered = 4 tires × 30,000 miles = 120,000 tire-miles. This wear is shared equally among 5 tires by rotation. Per tire = 120,000 / 5 = 24,000 miles. Tempting wrong: 30,000/5 = 6,000 ignores that 4 tires are used at once. 30,000 would mean no rotation. ANSWER 7: C Problem 8: List two-digit multiples of 7: 14,21,28,35,42,49,56,63,70,77,84,91,98. Compute digit sums: 1+4=5, 2+1=3, 2+8=10, 3+5=8, 4+2=6, 4+9=13, 5+6=11, 6+3=9, 7+0=7, 7+7=14, 8+4=12, 9+1=10, 9+8=17. Only two have sum 10: 28 and 91. Their sum = 28+91 = 119. ANSWER 8: A Problem 9: Volume of cylinder = π r^2 h, where r = diameter/2. Alex: diameter 6, so r=3. height 12. V_A = π × 3^2 × 12 = π × 9 × 12 = 108π. Felicia: diameter 12, so r=6. height 6. V_F = π × 6^2 × 6 = π × 36 × 6 = 216π. Ratio V_A : V_F = 108π : 216π = 108:216 = 1:2. Note volume scales with square of radius, so doubling diameter quadruples base area, outweighing halving height. ANSWER 9: B Problem 10: We need N > 2 with N ≡ 2 mod 3, mod 4, mod 5, mod 6. So N-2 is divisible by each of 3,4,5,6. N-2 must be a common multiple of 3,4,5,6. LCM(3,4,5,6): 4=2^2, 6=2×3, so LCM = 2^2 × 3 × 5 = 60. Positive multiples: 60,120,... N=2 gives N-2=0 which works but is excluded by >2. Next smallest is N-2 = 60, so N = 62. 62 is between 61 and 65. Check: 62 ÷ 3 =20 rem 2, ÷4=15 rem 2, etc. ANSWER 10: D |
openrouter:google/gemini-3.8-flash |
B | ✓ | showProblem 1:
**Restatement and Setup:**
We are given an item with an original price of $\$80$. It is discounted by $25\%$, and then a $10\%$ sales tax is applied to this discounted sale price. We need to find the final total selling price.
**Step-by-step computation:**
1. Calculate the discount:
$$\text{Discount} = 25\% \text{ of } \$80 = 0.25 \times 80 = \$20$$
2. Calculate the sale price:
$$\text{Sale Price} = \$80 - \$20 = \$60$$
*(Alternatively, the sale price is $75\%$ of $\$80$: $0.75 \times 80 = \$60$.)*
3. Calculate the tax on the sale price:
$$\text{Tax} = 10\% \text{ of } \$60 = 0.10 \times 60 = \$6$$
4. Calculate the total price:
$$\text{Total Price} = \$60 + \$6 = \$66$$
**Ruling out wrong choices:**
- Choice A ($\$45$) results from incorrectly subtracting both $25\%$ and $10\%$ from the original price, or similar errors.
- Choice B ($\$52$) and Choice C ($\$54$) are too low.
- Choice E ($\$68$) might occur if the tax were incorrectly computed on the original $\$80$ price ($80 \times 0.10 = \$8$) and added to $\$60$.
ANSWER 1: D
---
Problem 2:
**Restatement and Setup:**
Anh drives on two segments:
- Coastal access road: distance $d_c = 10$ miles, time $t_c = 30$ minutes.
- Highway: distance $d_h = 50$ miles.
He drives three times as fast on the highway as on the coastal access road ($v_h = 3 v_c$). We need to find the total time in minutes for the entire trip.
**Step-by-step computation:**
1. Find the speed on the coastal road:
Anh drives $10$ miles in $30$ minutes ($0.5$ hours).
$$v_c = \frac{10\text{ miles}}{0.5\text{ hours}} = 20\text{ mph}$$
2. Find the speed on the highway:
$$v_h = 3 \times v_c = 3 \times 20\text{ mph} = 60\text{ mph} = 1\text{ mile per minute}$$
3. Find the time spent on the highway:
$$t_h = \frac{50\text{ miles}}{1\text{ mile per minute}} = 50\text{ minutes}$$
4. Find the total trip time:
$$\text{Total time} = t_c + t_h = 30\text{ minutes} + 50\text{ minutes} = 80\text{ minutes}$$
**Ruling out wrong choices:**
- Choice A ($50$) is just the time on the highway.
- Choices B ($70$), D ($90$), and E ($100$) arise from miscalculating the highway speed ratio or mixing up minutes and hours.
ANSWER 2: C
---
Problem 3:
**Restatement and Setup:**
Given whole numbers (non-negative integers) $w, x, y, z$ such that:
$$2^w \cdot 3^x \cdot 5^y \cdot 7^z = 588$$
We need to find the value of $2w + 3x + 5y + 7z$.
**Step-by-step computation:**
1. Find the prime factorization of $588$:
$$588 = 2 \times 294 = 2 \times 2 \times 147 = 4 \times 3 \times 49 = 2^2 \times 3^1 \times 7^2$$
2. Matching the prime factors with $2^w \cdot 3^x \cdot 5^y \cdot 7^z$:
- $w = 2$
- $x = 1$
- $y = 0$ (since $5$ is not a factor of $588$)
- $z = 2$
3. Compute the required expression $2w + 3x + 5y + 7z$:
$$2(2) + 3(1) + 5(0) + 7(2) = 4 + 3 + 0 + 14 = 21$$
**Ruling out wrong choices:**
- If one mistakenly sets $y=1$, the sum would be $21 + 5 = 26$ (close to 25 or 27).
- Choices B, C, D, and E do not match the evaluated sum of $21$.
ANSWER 3: A
---
Problem 4:
**Restatement and Setup:**
Five runners (Luke, Melina, Nico, Olympia, Pedro) finished a race. We are given relative finish times:
- Nico finished $11$ minutes behind Pedro.
- Olympia finished $3$ minutes behind Pedro.
- Olympia finished $2$ minutes ahead of Melina.
- Olympia finished $6$ minutes ahead of Luke.
We need to determine who finished in fourth place.
**Step-by-step computation:**
Let Pedro's finish time be $t=0$ minutes (the earliest/winner).
- Pedro finishes at $0$ minutes.
- Olympia finished $3$ minutes behind Pedro $\implies$ Olympia finishes at $0 + 3 = 3$ minutes.
- Olympia finished $2$ minutes ahead of Melina $\implies$ Melina finishes $2$ minutes after Olympia $\implies 3 + 2 = 5$ minutes.
- Olympia finished $6$ minutes ahead of Luke $\implies$ Luke finishes $6$ minutes after Olympia $\implies 3 + 6 = 9$ minutes.
- Nico finished $11$ minutes behind Pedro $\implies$ Nico finishes at $0 + 11 = 11$ minutes.
Listing the runners in order of finish:
1. Pedro ($0$ min)
2. Olympia ($3$ min)
3. Melina ($5$ min)
4. Luke ($9$ min)
5. Nico ($11$ min)
Thus, Luke finished fourth.
**Ruling out wrong choices:**
- Pedro was 1st, Olympia was 2nd, Melina was 3rd, and Nico was 5th (last).
ANSWER 4: A
---
Problem 5:
**Restatement and Setup:**
Walter boards the bus at 7:30 a.m. and arrives home from the bus at 4:00 p.m.
During the day, he spends time on the bus (both ways) and at school.
School activities consist of:
- $6$ classes of $50$ minutes each
- $30$ minutes for lunch
- $2$ hours of additional time
We need to find the total time Walter spent on the bus.
**Step-by-step computation:**
1. Calculate total elapsed time between leaving home and returning:
- From 7:30 a.m. to 12:00 p.m. is $4$ hours and $30$ minutes ($4.5$ hours).
- From 12:00 p.m. to 4:00 p.m. is $4$ hours.
- Total elapsed time = $8$ hours and $30$ minutes $= 8 \times 60 + 30 = 510$ minutes.
2. Calculate total time spent on school activities:
- Classes: $6 \times 50\text{ minutes} = 300\text{ minutes}$
- Lunch: $30\text{ minutes}$
- Additional time: $2\text{ hours} = 120\text{ minutes}$
- Total school time $= 300 + 30 + 120 = 450\text{ minutes}$.
3. Calculate time spent on the bus:
$$\text{Bus time} = \text{Total time} - \text{School time} = 510 - 450 = 60\text{ minutes}$$
**Ruling out wrong choices:**
- 30 minutes assumes only a one-way trip or forgets additional school time.
- 75, 90, 120 minutes result from miscounting the elapsed time or forgetting the 30-minute lunch.
ANSWER 5: B
---
Problem 6:
**Restatement and Setup:**
Let $b$ be the number of boys and $g$ be the number of girls.
- Each boy receives $b$ jelly beans (total $b^2$).
- Each girl receives $g$ jelly beans (total $g^2$).
- Total jelly beans distributed: $400 - 6 = 394$.
- There are two more boys than girls: $b = g + 2$.
We need to find the total number of students in the class, which is $b + g$.
**Step-by-step com |
openrouter:~z-ai/glm-latest |
B | ✓ | show# Problem 1: **What is asked:** Find the final price after a 25% discount on $80, followed by 10% tax on the *sale price*. **Step 1 — Compute the sale price (25% off):** Discount = 25% of 80 = 0.25 × 80 = $20. Sale price = 80 − 20 = **$60**. **Step 2 — Add 10% tax to the sale price:** Tax = 10% of 60 = $6. Total = 60 + 6 = **$66**. **Rule out wrong answers:** - $52 (B) comes from wrongly taking 10% off the *original* price (60 − 8), but tax is added, not discounted. - $54 (C) comes from adding discounts: 80 × 0.75 × 0.9 — but tax increases the price. - The correct sequence is 80 → 60 → 66. ANSWER 1: D # Problem 2: **What is asked:** Find the total driving time in minutes. **Step 1 — Coastal road speed:** Anh drove 10 miles in 30 minutes (= 0.5 hour). Speed = 10 ÷ 0.5 = **20 mph**. **Step 2 — Highway speed:** He drove 3 times as fast: 3 × 20 = **60 mph**. **Step 3 — Highway time:** Time = distance ÷ speed = 50 ÷ 60 = 5/6 hour = **50 minutes**. **Step 4 — Total time:** 30 + 50 = **80 minutes**. **Rule out wrong answers:** - 90 (D) would result from wrongly assuming equal speeds (30 min + 60 min); but the highway was faster, so its time is *less* than 60 minutes. Only 80 fits. ANSWER 2: C # Problem 3: **What is asked:** Given 2^w · 3^x · 5^y · 7^z = 588, find 2w + 3x + 5y + 7z. **Step 1 — Factor 588:** 588 = 4 × 147 = 4 × 3 × 49 = 2² × 3 × 7². **Step 2 — Read off exponents:** 588 = 2² · 3¹ · 5⁰ · 7², so w = 2, x = 1, y = 0, z = 2. **Step 3 — Compute the expression:** 2w + 3x + 5y + 7z = 2(2) + 3(1) + 5(0) + 7(2) = 4 + 3 + 0 + 14 = **21**. **Rule out wrong answers:** 35 (D) or 56 (E) would come from confusing the coefficients 2,3,5,7 with the bases; note 588 is not divisible by 5, forcing y = 0. ANSWER 3: A # Problem 4: **What is asked:** Determine which runner finished fourth (in order of finishing time). **Step 1 — Set Pedro's time as P (a reference).** Then: - Nico finished 11 minutes behind Pedro: Nico = P + 11. - Olympia finished 3 minutes behind Pedro: Olympia = P + 3. - Olympia finished 2 minutes ahead of Melina, so Melina = P + 3 + 2 = P + 5. - Olympia finished 6 minutes ahead of Luke, so Luke = P + 3 + 6 = P + 9. **Step 2 — Order from fastest to slowest:** Pedro (P), Olympia (P+3), Melina (P+5), Luke (P+9), Nico (P+11). **Step 3 — Fourth place** is **Luke**. **Rule out wrong answers:** Nico (C) is last (5th), Pedro (E) is first; a common error is swapping Luke and Melina — but Luke = P+9 is behind Melina = P+5. ANSWER 4: A # Problem 5: **What is asked:** Total time Walter spent on the bus (both ways). **Step 1 — Total elapsed time from 7:30 a.m. to 4:00 p.m.:** That is 8 hours 30 minutes = 510 minutes. **Step 2 — Time accounted for at school:** - Classes: 6 × 50 = 300 minutes - Lunch: 30 minutes - Additional time: 2 hours = 120 minutes - Total school time: 300 + 30 + 120 = 450 minutes. **Step 3 — Bus time:** 510 − 450 = **60 minutes**. **Rule out wrong answers:** 90 (D) would ignore lunch or additional time; 30 (A) would count only one bus ride — but the round trip must be 60 minutes total. ANSWER 5: B # Problem 6: **What is asked:** Find the total number of students. **Step 1 — Set up equations.** Let g = number of girls, b = number of boys. Each boy gets b beans (b boys), each girl gets g beans (g girls): b² + g² = 400 − 6 = 394, and b = g + 2. **Step 2 — Substitute and solve:** (g+2)² + g² = 394 g² + 4g + 4 + g² = 394 2g² + 4g − 390 = 0 g² + 2g − 195 = 0 (g + 15)(g − 13) = 0 → g = 13 (reject −15). **Step 3 — Find the total:** Boys: b = 13 + 2 = 15. Total students = 15 + 13 = **28**. **Check:** 15² + 13² = 225 + 169 = 394 = 400 − 6. ✓ ANSWER 6: B # Problem 7: **What is asked:** Miles each of the 5 tires was used over 30,000 miles. **Step 1 — Total tire-miles used:** At any moment the car uses 4 tires. Over 30,000 miles, total tire-miles = 4 × 30,000 = 120,000. **Step 2 — Split equally among 5 tires:** 120,000 ÷ 5 = **24,000 miles** each. **Rule out wrong answers:** 30,000 (D) is wrong because no single tire can be used the whole time when 5 tires share the work; 6,000 (A) and 7,500 (B) wrongly divide by the wrong quantity (e.g., 30,000 ÷ 5 or ÷ 4). ANSWER 7: C # Problem 8: **What is asked:** Sum of the two two-digit multiples of 7 whose digits sum to 10. **Step 1 — List two-digit multiples of 7 and digit sums:** 14 (5), 21 (3), **28 (10)** ✓, 35 (8), 42 (6), 49 (13), 56 (11), 63 (9), 70 (7), 77 (14), 84 (12), **91 (10)** ✓, 98 (17). **Step 2 — Identify the two qualifying numbers:** 28 and 91. **Step 3 — Sum:** 28 + 91 = **119**. **Rule out wrong answers:** 126 (B) is 63 + 63 — impossible since numbers are distinct; 140 (D) might come from 28 + 112 (but 112 is three digits). ANSWER 8: A # Problem 9: **What is asked:** Ratio of Alex's can volume to Felicia's can volume. **Step 1 — Volume formula:** V = πr²h. **Step 2 — Alex's can:** diameter 6 → radius 3; height 12. V_A = π(3)²(12) = 108π. **Step 3 — Felicia's can:** diameter 12 → radius 6; height 6. V_F = π(6)²(6) = 216π. **Step 4 — Ratio:** V_A : V_F = 108π : 216π = **1 : 2**. **Rule out wrong answers:** 1:1 (C) is the tempting "swapped dimensions" intuition, but volume depends on the *square* of the radius, so doubling the radius quadruples that factor while halving the height only halves — net effect is Felicia's can is twice as big. ANSWER 9: B # Problem 10: **What is asked:** Find the smallest number > 2 that leaves remainder 2 when divided by 3, 4, 5, and 6, and identify the interval containing it. **Step 1 — Interpret the condition:** N − 2 must be divisible by 3, 4, 5, and 6, i.e., N − 2 is a multiple of LCM(3, 4, 5, 6). **Step 2 — Compute the LCM:** LCM(3,4,5,6) = 60 (since 60 is divisible by 3, 4, 5, and 6). **Step 3 — Candidates:** N = 60k + 2 for whole numbers k: N = 2, 62, 122, ... The smallest *greater than 2* is **62**. **Step 4 — Locate 62:** It lies between **61 and 65**. **Rule out wrong answers:** 42 + 2 = 44 is a common error (using 42, the LCM of only |
openrouter:qwen/qwen3.8-27b |
B | ✓ | showProblem 1:
The dress is originally priced at \$80. A 25% discount means the sale price is
\[
80(1-0.25)=80(0.75)=60.
\]
Then 10% tax is added to the sale price:
\[
60(1+0.10)=60(1.10)=66.
\]
So the total selling price is \$66.
ANSWER 1: D
Problem 2:
Anh drove 10 miles on the coastal road in 30 minutes, so his coastal-road speed was
\[
\frac{10\text{ miles}}{30\text{ minutes}}.
\]
He drove three times as fast on the highway. Therefore, for the same distance, the highway time would be one-third as long.
For 50 miles on the highway, if he had driven at coastal-road speed, it would take
\[
30 \times \frac{50}{10}=150
\]
minutes. But because he drove three times as fast on the highway, the actual highway time is
\[
\frac{150}{3}=50
\]
minutes.
The coastal road took 30 minutes, so the total trip time was
\[
30+50=80
\]
minutes.
ANSWER 2: C
Problem 3:
The equation should be read as
\[
2^w \cdot 3^x \cdot 5^y \cdot 7^z = 588.
\]
Factor 588:
\[
588=2\cdot 294=2^2\cdot 147=2^2\cdot 3\cdot 49=2^2\cdot 3^1\cdot 7^2.
\]
There is no factor of 5, so \(y=0\). Comparing prime exponents gives
\[
w=2,\qquad x=1,\qquad y=0,\qquad z=2.
\]
Now compute
\[
2w+3x+5y+7z=2(2)+3(1)+5(0)+7(2).
\]
\[
=4+3+0+14=21.
\]
ANSWER 3: A
Problem 4:
Let Pedro’s finishing time be \(P\). In a race, a smaller time means finishing earlier.
- Nico finished 11 minutes behind Pedro, so Nico’s time is
\[
P+11.
\]
- Olympia finished 3 minutes behind Pedro, so Olympia’s time is
\[
P+3.
\]
- Olympia finished 2 minutes ahead of Melina, so Melina’s time is
\[
(P+3)+2=P+5.
\]
- Olympia finished 6 minutes ahead of Luke, so Luke’s time is
\[
(P+3)+6=P+9.
\]
Now order the runners from first to last by increasing time:
\[
P,\quad P+3,\quad P+5,\quad P+9,\quad P+11.
\]
That is:
1. Pedro
2. Olympia
3. Melina
4. Luke
5. Nico
So the fourth runner was Luke.
ANSWER 4: A
Problem 5:
From 7:30 a.m. to 4:00 p.m. is 8 hours and 30 minutes:
\[
8(60)+30=480+30=510
\]
minutes.
Walter’s time in school not spent on the bus is:
- 6 classes of 50 minutes each:
\[
6(50)=300
\]
minutes;
- lunch: 30 minutes;
- additional time: 2 hours = 120 minutes.
Total non-bus time:
\[
300+30+120=450
\]
minutes.
So his total bus time was
\[
510-450=60
\]
minutes.
ANSWER 5: B
Problem 6:
Let the number of girls be \(g\). Since there were two more boys than girls, the number of boys is
\[
g+2.
\]
Mrs. Awesome gave each boy as many jelly beans as there were boys, so the boys received
\[
(g+2)^2
\]
jelly beans total. Each girl received as many as there were girls, so the girls received
\[
g^2
\]
jelly beans total.
She had 400 jelly beans and 6 left, so she gave away
\[
400-6=394.
\]
Thus,
\[
(g+2)^2+g^2=394.
\]
Expand:
\[
g^2+4g+4+g^2=394
\]
\[
2g^2+4g+4=394
\]
\[
2g^2+4g-390=0
\]
Divide by 2:
\[
g^2+2g-195=0.
\]
Factor:
\[
(g+15)(g-13)=0.
\]
Since \(g\) must be positive,
\[
g=13.
\]
Then the number of boys is
\[
13+2=15.
\]
The total number of students is
\[
13+15=28.
\]
ANSWER 6: B
Problem 7:
During the first 30,000 miles, the car was always using 4 tires at once. Therefore, the total “tire-miles” used is
\[
4 \times 30{,}000=120{,}000.
\]
There are 5 tires total, and they were all used the same number of miles. So each tire was used for
\[
\frac{120{,}000}{5}=24{,}000
\]
miles.
ANSWER 7: C
Problem 8:
We need two-digit multiples of 7 whose digits sum to 10.
The two-digit multiples of 7 are:
\[
14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84, 91, 98.
\]
Check digit sums:
\[
14: 1+4=5
\]
\[
21: 2+1=3
\]
\[
28: 2+8=10
\]
\[
35: 3+5=8
\]
\[
42: 4+2=6
\]
\[
49: 4+9=13
\]
\[
56: 5+6=11
\]
\[
63: 6+3=9
\]
\[
70: 7+0=7
\]
\[
77: 7+7=14
\]
\[
84: 8+4=12
\]
\[
91: 9+1=10
\]
\[
98: 9+8=17
\]
The only two are 28 and 91. Their sum is
\[
28+91=119.
\]
ANSWER 8: A
Problem 9:
The volume of a cylinder is
\[
V=\pi r^2h.
\]
Alex’s cans have diameter 6 cm, so radius 3 cm, and height 12 cm:
\[
V_A=\pi(3^2)(12)=\pi(9)(12)=108\pi.
\]
Felicia’s cans have diameter 12 cm, so radius 6 cm, and height 6 cm:
\[
V_F=\pi(6^2)(6)=\pi(36)(6)=216\pi.
\]
The ratio of Alex’s can volume to Felicia’s can volume is
\[
108\pi:216\pi=108:216=1:2.
\]
ANSWER 9: B
Problem 10:
Let the number be \(N\). It leaves a remainder of 2 when divided by 3, 4, 5, and 6, so
\[
N-2
\]
is divisible by 3, 4, 5, and 6. Therefore, \(N-2\) must be a multiple of the least common multiple of 3, 4, 5, and 6.
Find the LCM:
\[
\operatorname{lcm}(3,4,5,6)=60.
\]
So
\[
N-2=60k
\]
for some positive integer \(k\), because we need \(N>2\).
The smallest possible value is when \(k=1\):
\[
N-2=60
\]
\[
N=62.
\]
This lies between 61 and 65.
ANSWER 10: D |
openrouter:anthropic/claude-opus-5 |
B | ✓ | showProblem 1: Sale price: 25% off means you pay 75%: 80 × 0.75 = 60 dollars. Add 10% tax: 60 × 1.10 = 66 dollars. (Choice C, 54, would come from subtracting 10%; choice D is correct. Note taking 25% off then adding 10% doesn't return to 80.) ANSWER 1: D Problem 2: Coastal road: 10 miles in 30 minutes, so 3 minutes per mile. Highway speed is 3 times as fast, so 1 minute per mile. Highway time: 50 miles × 1 minute/mile = 50 minutes. Total: 50 + 30 = 80 minutes. (Choice A forgets the coastal 30 minutes; choice D would come from using 3 min/mile on the highway incorrectly.) ANSWER 2: C Problem 3: The equation is 2^w · 3^x · 5^y · 7^z = 588. Factor 588 = 4 · 147 = 2² · 3 · 7². So w = 2, x = 1, y = 0, z = 2. Then 2w + 3x + 5y + 7z = 2(2) + 3(1) + 5(0) + 7(2) = 4 + 3 + 0 + 14 = 21. ANSWER 3: A Problem 4: Let Pedro's time be 0 (he's a reference). - Nico = +11 - Olympia = +3 (3 min behind Pedro) - Melina = Olympia + 2 = +5 - Luke = Olympia + 6 = +9 Order from first: Pedro (0), Olympia (3), Melina (5), Luke (9), Nico (11). Fourth place is Luke. ANSWER 4: A Problem 5: Total time away: 7:30 a.m. to 4:00 p.m. = 8 hours 30 minutes = 510 minutes. Time at school: classes 6 × 50 = 300, lunch 30, extra 2 hours = 120; total 450 minutes. Bus time = 510 − 450 = 60 minutes (both trips combined). ANSWER 5: B Problem 6: Let g = number of girls, b = g + 2 boys. Jelly beans used: b² + g² = 400 − 6 = 394. (g + 2)² + g² = 394 → 2g² + 4g + 4 = 394 → g² + 2g − 195 = 0 → (g + 15)(g − 13) = 0 → g = 13. So girls = 13, boys = 15; check 169 + 225 = 394 ✓. Total students = 28. ANSWER 6: B Problem 7: Four tires are on the road at any time, so total tire-miles = 4 × 30,000 = 120,000. Shared equally among 5 tires: 120,000 ÷ 5 = 24,000 miles each. (30,000 would be if no rotation; 6,000 is the rest time per tire, not use.) ANSWER 7: C Problem 8: Two-digit multiples of 7: 14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84, 91, 98. Digit sums: 5, 3, 10, 8, 6, 13, 11, 9, 7, 14, 12, 10, 17. Digit sum 10 occurs for 28 and 91. Sum: 28 + 91 = 119. ANSWER 8: A Problem 9: Alex: diameter 6 → radius 3, height 12: V = π(3²)(12) = 108π. Felicia: diameter 12 → radius 6, height 6: V = π(6²)(6) = 216π. Ratio = 108π : 216π = 1 : 2. (Doubling the radius quadruples volume, while halving height only halves it, so Felicia's is twice as big — not equal.) ANSWER 9: B Problem 10: A number leaving remainder 2 when divided by 3, 4, 5, and 6 must be 2 more than a common multiple of 3, 4, 5, 6. LCM(3, 4, 5, 6) = 60, so the smallest such number greater than 2 is 60 + 2 = 62. 62 lies between 61 and 65. ANSWER 10: D |
openrouter:openai/gpt-5.6-terra-pro |
B | ✓ | showProblem 1:
The dress was originally priced at \$80.
A 25% discount means the sale price is \(75\%\) of the original price:
\[
80 \times 0.75=60
\]
Then 10% tax is added:
\[
10\% \text{ of } 60 = 6
\]
So the total price is
\[
60+6=66
\]
A common mistake is to subtract 25% and add 10% of the original \$80, but the tax is added to the reduced sale price, not the original price.
\[
\boxed{66}
\]
ANSWER 1: D
Problem 2:
Anh drove 10 miles on the coastal road in 30 minutes.
Since 30 minutes is \(\frac12\) hour, his coastal-road speed was
\[
\frac{10\text{ miles}}{\frac12\text{ hour}}=20\text{ miles per hour}
\]
He drove three times as fast on the highway:
\[
3(20)=60\text{ miles per hour}
\]
The highway trip was 50 miles, so the highway driving time was
\[
\frac{50}{60}\text{ hour}=\frac56\text{ hour}
\]
Convert \(\frac56\) hour to minutes:
\[
\frac56\cdot 60=50\text{ minutes}
\]
His total driving time was
\[
30+50=80\text{ minutes}
\]
The answer is not 50 minutes, since that is only the highway time.
\[
\boxed{80}
\]
ANSWER 2: C
Problem 3:
We are told that
\[
2^w\cdot 3^x\cdot 5^y\cdot 7^z=588
\]
Factor 588 into primes:
\[
588=2\cdot 294=2^2\cdot 147=2^2\cdot 3\cdot 49
\]
Thus,
\[
588=2^2\cdot 3^1\cdot 5^0\cdot 7^2
\]
So
\[
w=2,\qquad x=1,\qquad y=0,\qquad z=2
\]
Now calculate:
\[
2w+3x+5y+7z
\]
\[
=2(2)+3(1)+5(0)+7(2)
\]
\[
=4+3+0+14=21
\]
The factor \(5^0\) is important: since 588 has no factor of 5, \(y=0\), not 1.
\[
\boxed{21}
\]
ANSWER 3: A
Problem 4:
We compare all runners’ finishing times relative to Pedro.
- Nico finished 11 minutes behind Pedro.
- Olympia finished 3 minutes behind Pedro.
- Olympia finished 2 minutes ahead of Melina, so Melina finished 2 minutes behind Olympia.
- Olympia finished 6 minutes ahead of Luke, so Luke finished 6 minutes behind Olympia.
Let Pedro finish at time 0.
Then:
\[
\begin{array}{c|c}
\text{Runner} & \text{Minutes behind Pedro} \\
\hline
\text{Pedro} & 0\\
\text{Olympia} & 3\\
\text{Melina} & 3+2=5\\
\text{Luke} & 3+6=9\\
\text{Nico} & 11
\end{array}
\]
Therefore, the order is:
1. Pedro
2. Olympia
3. Melina
4. Luke
5. Nico
So Luke finished fourth.
\[
\boxed{\text{Luke}}
\]
ANSWER 4: A
Problem 5:
Walter is at school from 7:30 a.m. until 4:00 p.m.
That is:
\[
8\text{ hours }30\text{ minutes}=510\text{ minutes}
\]
His school-day activities take:
- 6 classes of 50 minutes each:
\[
6\cdot 50=300\text{ minutes}
\]
- Lunch:
\[
30\text{ minutes}
\]
- Additional school time:
\[
2\text{ hours}=120\text{ minutes}
\]
Total time not spent on the bus:
\[
300+30+120=450\text{ minutes}
\]
Therefore, bus time is
\[
510-450=60\text{ minutes}
\]
This includes both the ride to school and the ride home.
\[
\boxed{60}
\]
ANSWER 5: B
Problem 6:
Let the number of girls be \(g\).
There are two more boys than girls, so the number of boys is
\[
g+2
\]
Each boy receives as many jelly beans as there are boys, so the boys receive
\[
(g+2)(g+2)=(g+2)^2
\]
jelly beans altogether.
Each girl receives \(g\) jelly beans, so the girls receive
\[
g^2
\]
jelly beans altogether.
Mrs. Awesome gave away
\[
400-6=394
\]
jelly beans. Therefore,
\[
g^2+(g+2)^2=394
\]
Expand:
\[
g^2+g^2+4g+4=394
\]
\[
2g^2+4g-390=0
\]
Divide by 2:
\[
g^2+2g-195=0
\]
Factor:
\[
(g+15)(g-13)=0
\]
So
\[
g=13
\]
since a number of girls cannot be negative.
Thus boys:
\[
13+2=15
\]
Total students:
\[
13+15=28
\]
\[
\boxed{28}
\]
ANSWER 6: B
Problem 7:
During the first 30,000 miles, the car always uses 4 tires on the road.
So the total number of tire-miles used is
\[
4\cdot 30{,}000=120{,}000
\]
There are 5 tires total, and they were rotated so each tire was used equally.
Therefore, each tire was used
\[
\frac{120{,}000}{5}=24{,}000
\]
miles.
It is not 30,000 miles because only four of the five tires are being driven on at any one time.
\[
\boxed{24{,}000}
\]
ANSWER 7: C
Problem 8:
We need two-digit multiples of 7 whose digits add to 10.
The two-digit multiples of 7 are:
\[
14,21,28,35,42,49,56,63,70,77,84,91,98
\]
Check digit sums:
\[
28:\quad 2+8=10
\]
\[
91:\quad 9+1=10
\]
These are the only two.
Their sum is
\[
28+91=119
\]
\[
\boxed{119}
\]
ANSWER 8: A
Problem 9:
The volume of a cylinder is
\[
V=\pi r^2h
\]
For Alex’s can:
- Diameter \(=6\), so radius \(=3\)
- Height \(=12\)
\[
V_A=\pi(3)^2(12)=108\pi
\]
For Felicia’s can:
- Diameter \(=12\), so radius \(=6\)
- Height \(=6\)
\[
V_F=\pi(6)^2(6)=216\pi
\]
The ratio of Alex’s volume to Felicia’s volume is
\[
108\pi:216\pi
\]
Divide both parts by \(108\pi\):
\[
1:2
\]
Although Alex’s can is twice as tall, Felicia’s radius is twice as large, and radius is squared in the volume formula.
\[
\boxed{1:2}
\]
ANSWER 9: B
Problem 10:
We seek the smallest number greater than 2 that leaves remainder 2 when divided by 3, 4, 5, and 6.
If the number is \(n\), then \(n-2\) must be divisible by all of
\[
3,\ 4,\ 5,\ 6
\]
The least common multiple is
\[
\operatorname{lcm}(3,4,5,6)=60
\]
So the smallest possible value of \(n-2\) is 60:
\[
n-2=60
\]
\[
n=62
\]
The number 62 lies between 61 and 65.
Indeed:
\[
62\div 3,\ 62\div 4,\ 62\div 5,\ 62\div 6
\]
all leave remainder 2.
\[
\boxed{61\text{ and }65}
\]
ANSWER 10: D |
The five tires of a car (four road tires and a full-sized spare) were rotated so that each tire was used the same number of miles during the first 30,000 miles the car traveled. For how many miles was each tire used?
| Model | Pick | ✓/✗ | Reasoning |
|---|---|---|---|
openrouter:meta/muse-spark-1.3 |
C | ✓ | showProblem 1: We are asked for the final price after a discount and then tax. Original price is 80 dollars. 25% off means pay 100% - 25% = 75% of original. Sale price = 0.75 × 80 = 60 dollars. Tempting mistake: subtract 25 dollars to get 55. No, 25% means percent, not dollars. Then 10% tax is added to the sale price, not the original price. Tax = 10% of 60 = 6 dollars. Total = 60 + 6 = 66 dollars. Equivalently 1.10 × 60 = 66. Check: A 45 is far too low. B 52 would be 35% off total. C 54 would be adding tax incorrectly. E 68 would be adding 10% of 80. ANSWER 1: D Problem 2: We need total time = time on coastal road + time on highway. Given time on coastal road = 30 minutes for 10 miles. Let coastal speed = v. Then v = 10 miles / 30 min. Highway speed is three times as fast: 3v. Highway distance is 50 miles. Time = distance / speed, so: Highway time = 50 / (3v). From coastal: 10 / v = 30, so 1/v = 3 min per mile. Thus highway time = 50 / 3 × (1/v) = 50/3 × 3 = 50 minutes. Total = 30 + 50 = 80 minutes. Alternative check: Highway is 5 times distance but 3 times speed, so takes 5/3 as long as coastal: 30 × 5/3 = 50. ANSWER 2: C Problem 3: We are told w,x,y,z are whole numbers, so 0,1,2,... And 2^w · 3^x · 5^y · 7^z = 588. Find 2w + 3x + 5y + 7z. Factor 588 into primes. 588 = 58.8 × 10, but do integer: 588 = 2 × 294 = 2 × 2 × 147 = 4 × 147. 147 = 3 × 49 = 3 × 7 × 7. So 588 = 2^2 × 3^1 × 5^0 × 7^2. By uniqueness of prime factorization, exponents must match: w = 2, x = 1, y = 0, z = 2. Note y=0 is allowed because whole numbers include 0, and 5^0 = 1. Now compute linear expression: 2w + 3x + 5y + 7z = 2×2 + 3×1 + 5×0 + 7×2 = 4 + 3 + 0 + 14 = 21. ANSWER 3: A Problem 4: Order the five finishers by time behind Pedro. Let Pedro's time be P. Nico finished 11 minutes behind Pedro: N = P+11. Olympia finished 3 minutes behind Pedro: O = P+3. Olympia finished 2 minutes ahead of Melina: So Melina is 2 minutes behind Olympia: M = O+2 = P+5. Olympia finished 6 minutes ahead of Luke: So Luke is 6 minutes behind Olympia: L = O+6 = P+9. Order by increasing time: Pedro at P+0 — 1st Olympia at P+3 — 2nd Melina at P+5 — 3rd Luke at P+9 — 4th Nico at P+11 — 5th So fourth is Luke. ANSWER 4: A Problem 5: Total elapsed time from boarding morning bus to arriving home. From 7:30 a.m. to 4:00 p.m. = 8.5 hours = 8×60 + 30 = 510 minutes. Time at school: 6 classes × 50 min = 300 min. Lunch 30 min. Additional 2 hours = 120 min. Total school = 300 + 30 + 120 = 450 min. Bus time (morning + afternoon) = total elapsed - school time = 510 - 450 = 60 minutes. Tempting error: miscount 7:30 to 4:00 as 8 hours. ANSWER 5: B Problem 6: Let g = number of girls. Then number of boys b = g+2. Each boy gets b beans, so boys total = b × b = b^2. Each girl gets g beans, so girls total = g × g = g^2. Beans used = 400 - 6 left = 394. So b^2 + g^2 = 394. Substitute: (g+2)^2 + g^2 = 394 g^2 + 4g + 4 + g^2 = 394 2g^2 + 4g - 390 = 0 Divide 2: g^2 + 2g - 195 = 0. Factor 195 = 13 × 15, differing by 2: (g+15)(g-13)=0. Positive solution g = 13. Then b = 15. Total students = 13+15 = 28. Check: 15^2+13^2 =225+169=394 correct. ANSWER 6: B Problem 7: The car travels 30,000 miles. At any moment exactly 4 tires are on the road carrying it. Total tire-miles delivered = 4 tires × 30,000 miles = 120,000 tire-miles. This wear is shared equally among 5 tires by rotation. Per tire = 120,000 / 5 = 24,000 miles. Tempting wrong: 30,000/5 = 6,000 ignores that 4 tires are used at once. 30,000 would mean no rotation. ANSWER 7: C Problem 8: List two-digit multiples of 7: 14,21,28,35,42,49,56,63,70,77,84,91,98. Compute digit sums: 1+4=5, 2+1=3, 2+8=10, 3+5=8, 4+2=6, 4+9=13, 5+6=11, 6+3=9, 7+0=7, 7+7=14, 8+4=12, 9+1=10, 9+8=17. Only two have sum 10: 28 and 91. Their sum = 28+91 = 119. ANSWER 8: A Problem 9: Volume of cylinder = π r^2 h, where r = diameter/2. Alex: diameter 6, so r=3. height 12. V_A = π × 3^2 × 12 = π × 9 × 12 = 108π. Felicia: diameter 12, so r=6. height 6. V_F = π × 6^2 × 6 = π × 36 × 6 = 216π. Ratio V_A : V_F = 108π : 216π = 108:216 = 1:2. Note volume scales with square of radius, so doubling diameter quadruples base area, outweighing halving height. ANSWER 9: B Problem 10: We need N > 2 with N ≡ 2 mod 3, mod 4, mod 5, mod 6. So N-2 is divisible by each of 3,4,5,6. N-2 must be a common multiple of 3,4,5,6. LCM(3,4,5,6): 4=2^2, 6=2×3, so LCM = 2^2 × 3 × 5 = 60. Positive multiples: 60,120,... N=2 gives N-2=0 which works but is excluded by >2. Next smallest is N-2 = 60, so N = 62. 62 is between 61 and 65. Check: 62 ÷ 3 =20 rem 2, ÷4=15 rem 2, etc. ANSWER 10: D |
openrouter:google/gemini-3.8-flash |
C | ✓ | showProblem 1:
**Restatement and Setup:**
We are given an item with an original price of $\$80$. It is discounted by $25\%$, and then a $10\%$ sales tax is applied to this discounted sale price. We need to find the final total selling price.
**Step-by-step computation:**
1. Calculate the discount:
$$\text{Discount} = 25\% \text{ of } \$80 = 0.25 \times 80 = \$20$$
2. Calculate the sale price:
$$\text{Sale Price} = \$80 - \$20 = \$60$$
*(Alternatively, the sale price is $75\%$ of $\$80$: $0.75 \times 80 = \$60$.)*
3. Calculate the tax on the sale price:
$$\text{Tax} = 10\% \text{ of } \$60 = 0.10 \times 60 = \$6$$
4. Calculate the total price:
$$\text{Total Price} = \$60 + \$6 = \$66$$
**Ruling out wrong choices:**
- Choice A ($\$45$) results from incorrectly subtracting both $25\%$ and $10\%$ from the original price, or similar errors.
- Choice B ($\$52$) and Choice C ($\$54$) are too low.
- Choice E ($\$68$) might occur if the tax were incorrectly computed on the original $\$80$ price ($80 \times 0.10 = \$8$) and added to $\$60$.
ANSWER 1: D
---
Problem 2:
**Restatement and Setup:**
Anh drives on two segments:
- Coastal access road: distance $d_c = 10$ miles, time $t_c = 30$ minutes.
- Highway: distance $d_h = 50$ miles.
He drives three times as fast on the highway as on the coastal access road ($v_h = 3 v_c$). We need to find the total time in minutes for the entire trip.
**Step-by-step computation:**
1. Find the speed on the coastal road:
Anh drives $10$ miles in $30$ minutes ($0.5$ hours).
$$v_c = \frac{10\text{ miles}}{0.5\text{ hours}} = 20\text{ mph}$$
2. Find the speed on the highway:
$$v_h = 3 \times v_c = 3 \times 20\text{ mph} = 60\text{ mph} = 1\text{ mile per minute}$$
3. Find the time spent on the highway:
$$t_h = \frac{50\text{ miles}}{1\text{ mile per minute}} = 50\text{ minutes}$$
4. Find the total trip time:
$$\text{Total time} = t_c + t_h = 30\text{ minutes} + 50\text{ minutes} = 80\text{ minutes}$$
**Ruling out wrong choices:**
- Choice A ($50$) is just the time on the highway.
- Choices B ($70$), D ($90$), and E ($100$) arise from miscalculating the highway speed ratio or mixing up minutes and hours.
ANSWER 2: C
---
Problem 3:
**Restatement and Setup:**
Given whole numbers (non-negative integers) $w, x, y, z$ such that:
$$2^w \cdot 3^x \cdot 5^y \cdot 7^z = 588$$
We need to find the value of $2w + 3x + 5y + 7z$.
**Step-by-step computation:**
1. Find the prime factorization of $588$:
$$588 = 2 \times 294 = 2 \times 2 \times 147 = 4 \times 3 \times 49 = 2^2 \times 3^1 \times 7^2$$
2. Matching the prime factors with $2^w \cdot 3^x \cdot 5^y \cdot 7^z$:
- $w = 2$
- $x = 1$
- $y = 0$ (since $5$ is not a factor of $588$)
- $z = 2$
3. Compute the required expression $2w + 3x + 5y + 7z$:
$$2(2) + 3(1) + 5(0) + 7(2) = 4 + 3 + 0 + 14 = 21$$
**Ruling out wrong choices:**
- If one mistakenly sets $y=1$, the sum would be $21 + 5 = 26$ (close to 25 or 27).
- Choices B, C, D, and E do not match the evaluated sum of $21$.
ANSWER 3: A
---
Problem 4:
**Restatement and Setup:**
Five runners (Luke, Melina, Nico, Olympia, Pedro) finished a race. We are given relative finish times:
- Nico finished $11$ minutes behind Pedro.
- Olympia finished $3$ minutes behind Pedro.
- Olympia finished $2$ minutes ahead of Melina.
- Olympia finished $6$ minutes ahead of Luke.
We need to determine who finished in fourth place.
**Step-by-step computation:**
Let Pedro's finish time be $t=0$ minutes (the earliest/winner).
- Pedro finishes at $0$ minutes.
- Olympia finished $3$ minutes behind Pedro $\implies$ Olympia finishes at $0 + 3 = 3$ minutes.
- Olympia finished $2$ minutes ahead of Melina $\implies$ Melina finishes $2$ minutes after Olympia $\implies 3 + 2 = 5$ minutes.
- Olympia finished $6$ minutes ahead of Luke $\implies$ Luke finishes $6$ minutes after Olympia $\implies 3 + 6 = 9$ minutes.
- Nico finished $11$ minutes behind Pedro $\implies$ Nico finishes at $0 + 11 = 11$ minutes.
Listing the runners in order of finish:
1. Pedro ($0$ min)
2. Olympia ($3$ min)
3. Melina ($5$ min)
4. Luke ($9$ min)
5. Nico ($11$ min)
Thus, Luke finished fourth.
**Ruling out wrong choices:**
- Pedro was 1st, Olympia was 2nd, Melina was 3rd, and Nico was 5th (last).
ANSWER 4: A
---
Problem 5:
**Restatement and Setup:**
Walter boards the bus at 7:30 a.m. and arrives home from the bus at 4:00 p.m.
During the day, he spends time on the bus (both ways) and at school.
School activities consist of:
- $6$ classes of $50$ minutes each
- $30$ minutes for lunch
- $2$ hours of additional time
We need to find the total time Walter spent on the bus.
**Step-by-step computation:**
1. Calculate total elapsed time between leaving home and returning:
- From 7:30 a.m. to 12:00 p.m. is $4$ hours and $30$ minutes ($4.5$ hours).
- From 12:00 p.m. to 4:00 p.m. is $4$ hours.
- Total elapsed time = $8$ hours and $30$ minutes $= 8 \times 60 + 30 = 510$ minutes.
2. Calculate total time spent on school activities:
- Classes: $6 \times 50\text{ minutes} = 300\text{ minutes}$
- Lunch: $30\text{ minutes}$
- Additional time: $2\text{ hours} = 120\text{ minutes}$
- Total school time $= 300 + 30 + 120 = 450\text{ minutes}$.
3. Calculate time spent on the bus:
$$\text{Bus time} = \text{Total time} - \text{School time} = 510 - 450 = 60\text{ minutes}$$
**Ruling out wrong choices:**
- 30 minutes assumes only a one-way trip or forgets additional school time.
- 75, 90, 120 minutes result from miscounting the elapsed time or forgetting the 30-minute lunch.
ANSWER 5: B
---
Problem 6:
**Restatement and Setup:**
Let $b$ be the number of boys and $g$ be the number of girls.
- Each boy receives $b$ jelly beans (total $b^2$).
- Each girl receives $g$ jelly beans (total $g^2$).
- Total jelly beans distributed: $400 - 6 = 394$.
- There are two more boys than girls: $b = g + 2$.
We need to find the total number of students in the class, which is $b + g$.
**Step-by-step com |
openrouter:~z-ai/glm-latest |
C | ✓ | show# Problem 1: **What is asked:** Find the final price after a 25% discount on $80, followed by 10% tax on the *sale price*. **Step 1 — Compute the sale price (25% off):** Discount = 25% of 80 = 0.25 × 80 = $20. Sale price = 80 − 20 = **$60**. **Step 2 — Add 10% tax to the sale price:** Tax = 10% of 60 = $6. Total = 60 + 6 = **$66**. **Rule out wrong answers:** - $52 (B) comes from wrongly taking 10% off the *original* price (60 − 8), but tax is added, not discounted. - $54 (C) comes from adding discounts: 80 × 0.75 × 0.9 — but tax increases the price. - The correct sequence is 80 → 60 → 66. ANSWER 1: D # Problem 2: **What is asked:** Find the total driving time in minutes. **Step 1 — Coastal road speed:** Anh drove 10 miles in 30 minutes (= 0.5 hour). Speed = 10 ÷ 0.5 = **20 mph**. **Step 2 — Highway speed:** He drove 3 times as fast: 3 × 20 = **60 mph**. **Step 3 — Highway time:** Time = distance ÷ speed = 50 ÷ 60 = 5/6 hour = **50 minutes**. **Step 4 — Total time:** 30 + 50 = **80 minutes**. **Rule out wrong answers:** - 90 (D) would result from wrongly assuming equal speeds (30 min + 60 min); but the highway was faster, so its time is *less* than 60 minutes. Only 80 fits. ANSWER 2: C # Problem 3: **What is asked:** Given 2^w · 3^x · 5^y · 7^z = 588, find 2w + 3x + 5y + 7z. **Step 1 — Factor 588:** 588 = 4 × 147 = 4 × 3 × 49 = 2² × 3 × 7². **Step 2 — Read off exponents:** 588 = 2² · 3¹ · 5⁰ · 7², so w = 2, x = 1, y = 0, z = 2. **Step 3 — Compute the expression:** 2w + 3x + 5y + 7z = 2(2) + 3(1) + 5(0) + 7(2) = 4 + 3 + 0 + 14 = **21**. **Rule out wrong answers:** 35 (D) or 56 (E) would come from confusing the coefficients 2,3,5,7 with the bases; note 588 is not divisible by 5, forcing y = 0. ANSWER 3: A # Problem 4: **What is asked:** Determine which runner finished fourth (in order of finishing time). **Step 1 — Set Pedro's time as P (a reference).** Then: - Nico finished 11 minutes behind Pedro: Nico = P + 11. - Olympia finished 3 minutes behind Pedro: Olympia = P + 3. - Olympia finished 2 minutes ahead of Melina, so Melina = P + 3 + 2 = P + 5. - Olympia finished 6 minutes ahead of Luke, so Luke = P + 3 + 6 = P + 9. **Step 2 — Order from fastest to slowest:** Pedro (P), Olympia (P+3), Melina (P+5), Luke (P+9), Nico (P+11). **Step 3 — Fourth place** is **Luke**. **Rule out wrong answers:** Nico (C) is last (5th), Pedro (E) is first; a common error is swapping Luke and Melina — but Luke = P+9 is behind Melina = P+5. ANSWER 4: A # Problem 5: **What is asked:** Total time Walter spent on the bus (both ways). **Step 1 — Total elapsed time from 7:30 a.m. to 4:00 p.m.:** That is 8 hours 30 minutes = 510 minutes. **Step 2 — Time accounted for at school:** - Classes: 6 × 50 = 300 minutes - Lunch: 30 minutes - Additional time: 2 hours = 120 minutes - Total school time: 300 + 30 + 120 = 450 minutes. **Step 3 — Bus time:** 510 − 450 = **60 minutes**. **Rule out wrong answers:** 90 (D) would ignore lunch or additional time; 30 (A) would count only one bus ride — but the round trip must be 60 minutes total. ANSWER 5: B # Problem 6: **What is asked:** Find the total number of students. **Step 1 — Set up equations.** Let g = number of girls, b = number of boys. Each boy gets b beans (b boys), each girl gets g beans (g girls): b² + g² = 400 − 6 = 394, and b = g + 2. **Step 2 — Substitute and solve:** (g+2)² + g² = 394 g² + 4g + 4 + g² = 394 2g² + 4g − 390 = 0 g² + 2g − 195 = 0 (g + 15)(g − 13) = 0 → g = 13 (reject −15). **Step 3 — Find the total:** Boys: b = 13 + 2 = 15. Total students = 15 + 13 = **28**. **Check:** 15² + 13² = 225 + 169 = 394 = 400 − 6. ✓ ANSWER 6: B # Problem 7: **What is asked:** Miles each of the 5 tires was used over 30,000 miles. **Step 1 — Total tire-miles used:** At any moment the car uses 4 tires. Over 30,000 miles, total tire-miles = 4 × 30,000 = 120,000. **Step 2 — Split equally among 5 tires:** 120,000 ÷ 5 = **24,000 miles** each. **Rule out wrong answers:** 30,000 (D) is wrong because no single tire can be used the whole time when 5 tires share the work; 6,000 (A) and 7,500 (B) wrongly divide by the wrong quantity (e.g., 30,000 ÷ 5 or ÷ 4). ANSWER 7: C # Problem 8: **What is asked:** Sum of the two two-digit multiples of 7 whose digits sum to 10. **Step 1 — List two-digit multiples of 7 and digit sums:** 14 (5), 21 (3), **28 (10)** ✓, 35 (8), 42 (6), 49 (13), 56 (11), 63 (9), 70 (7), 77 (14), 84 (12), **91 (10)** ✓, 98 (17). **Step 2 — Identify the two qualifying numbers:** 28 and 91. **Step 3 — Sum:** 28 + 91 = **119**. **Rule out wrong answers:** 126 (B) is 63 + 63 — impossible since numbers are distinct; 140 (D) might come from 28 + 112 (but 112 is three digits). ANSWER 8: A # Problem 9: **What is asked:** Ratio of Alex's can volume to Felicia's can volume. **Step 1 — Volume formula:** V = πr²h. **Step 2 — Alex's can:** diameter 6 → radius 3; height 12. V_A = π(3)²(12) = 108π. **Step 3 — Felicia's can:** diameter 12 → radius 6; height 6. V_F = π(6)²(6) = 216π. **Step 4 — Ratio:** V_A : V_F = 108π : 216π = **1 : 2**. **Rule out wrong answers:** 1:1 (C) is the tempting "swapped dimensions" intuition, but volume depends on the *square* of the radius, so doubling the radius quadruples that factor while halving the height only halves — net effect is Felicia's can is twice as big. ANSWER 9: B # Problem 10: **What is asked:** Find the smallest number > 2 that leaves remainder 2 when divided by 3, 4, 5, and 6, and identify the interval containing it. **Step 1 — Interpret the condition:** N − 2 must be divisible by 3, 4, 5, and 6, i.e., N − 2 is a multiple of LCM(3, 4, 5, 6). **Step 2 — Compute the LCM:** LCM(3,4,5,6) = 60 (since 60 is divisible by 3, 4, 5, and 6). **Step 3 — Candidates:** N = 60k + 2 for whole numbers k: N = 2, 62, 122, ... The smallest *greater than 2* is **62**. **Step 4 — Locate 62:** It lies between **61 and 65**. **Rule out wrong answers:** 42 + 2 = 44 is a common error (using 42, the LCM of only |
openrouter:qwen/qwen3.8-27b |
C | ✓ | showProblem 1:
The dress is originally priced at \$80. A 25% discount means the sale price is
\[
80(1-0.25)=80(0.75)=60.
\]
Then 10% tax is added to the sale price:
\[
60(1+0.10)=60(1.10)=66.
\]
So the total selling price is \$66.
ANSWER 1: D
Problem 2:
Anh drove 10 miles on the coastal road in 30 minutes, so his coastal-road speed was
\[
\frac{10\text{ miles}}{30\text{ minutes}}.
\]
He drove three times as fast on the highway. Therefore, for the same distance, the highway time would be one-third as long.
For 50 miles on the highway, if he had driven at coastal-road speed, it would take
\[
30 \times \frac{50}{10}=150
\]
minutes. But because he drove three times as fast on the highway, the actual highway time is
\[
\frac{150}{3}=50
\]
minutes.
The coastal road took 30 minutes, so the total trip time was
\[
30+50=80
\]
minutes.
ANSWER 2: C
Problem 3:
The equation should be read as
\[
2^w \cdot 3^x \cdot 5^y \cdot 7^z = 588.
\]
Factor 588:
\[
588=2\cdot 294=2^2\cdot 147=2^2\cdot 3\cdot 49=2^2\cdot 3^1\cdot 7^2.
\]
There is no factor of 5, so \(y=0\). Comparing prime exponents gives
\[
w=2,\qquad x=1,\qquad y=0,\qquad z=2.
\]
Now compute
\[
2w+3x+5y+7z=2(2)+3(1)+5(0)+7(2).
\]
\[
=4+3+0+14=21.
\]
ANSWER 3: A
Problem 4:
Let Pedro’s finishing time be \(P\). In a race, a smaller time means finishing earlier.
- Nico finished 11 minutes behind Pedro, so Nico’s time is
\[
P+11.
\]
- Olympia finished 3 minutes behind Pedro, so Olympia’s time is
\[
P+3.
\]
- Olympia finished 2 minutes ahead of Melina, so Melina’s time is
\[
(P+3)+2=P+5.
\]
- Olympia finished 6 minutes ahead of Luke, so Luke’s time is
\[
(P+3)+6=P+9.
\]
Now order the runners from first to last by increasing time:
\[
P,\quad P+3,\quad P+5,\quad P+9,\quad P+11.
\]
That is:
1. Pedro
2. Olympia
3. Melina
4. Luke
5. Nico
So the fourth runner was Luke.
ANSWER 4: A
Problem 5:
From 7:30 a.m. to 4:00 p.m. is 8 hours and 30 minutes:
\[
8(60)+30=480+30=510
\]
minutes.
Walter’s time in school not spent on the bus is:
- 6 classes of 50 minutes each:
\[
6(50)=300
\]
minutes;
- lunch: 30 minutes;
- additional time: 2 hours = 120 minutes.
Total non-bus time:
\[
300+30+120=450
\]
minutes.
So his total bus time was
\[
510-450=60
\]
minutes.
ANSWER 5: B
Problem 6:
Let the number of girls be \(g\). Since there were two more boys than girls, the number of boys is
\[
g+2.
\]
Mrs. Awesome gave each boy as many jelly beans as there were boys, so the boys received
\[
(g+2)^2
\]
jelly beans total. Each girl received as many as there were girls, so the girls received
\[
g^2
\]
jelly beans total.
She had 400 jelly beans and 6 left, so she gave away
\[
400-6=394.
\]
Thus,
\[
(g+2)^2+g^2=394.
\]
Expand:
\[
g^2+4g+4+g^2=394
\]
\[
2g^2+4g+4=394
\]
\[
2g^2+4g-390=0
\]
Divide by 2:
\[
g^2+2g-195=0.
\]
Factor:
\[
(g+15)(g-13)=0.
\]
Since \(g\) must be positive,
\[
g=13.
\]
Then the number of boys is
\[
13+2=15.
\]
The total number of students is
\[
13+15=28.
\]
ANSWER 6: B
Problem 7:
During the first 30,000 miles, the car was always using 4 tires at once. Therefore, the total “tire-miles” used is
\[
4 \times 30{,}000=120{,}000.
\]
There are 5 tires total, and they were all used the same number of miles. So each tire was used for
\[
\frac{120{,}000}{5}=24{,}000
\]
miles.
ANSWER 7: C
Problem 8:
We need two-digit multiples of 7 whose digits sum to 10.
The two-digit multiples of 7 are:
\[
14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84, 91, 98.
\]
Check digit sums:
\[
14: 1+4=5
\]
\[
21: 2+1=3
\]
\[
28: 2+8=10
\]
\[
35: 3+5=8
\]
\[
42: 4+2=6
\]
\[
49: 4+9=13
\]
\[
56: 5+6=11
\]
\[
63: 6+3=9
\]
\[
70: 7+0=7
\]
\[
77: 7+7=14
\]
\[
84: 8+4=12
\]
\[
91: 9+1=10
\]
\[
98: 9+8=17
\]
The only two are 28 and 91. Their sum is
\[
28+91=119.
\]
ANSWER 8: A
Problem 9:
The volume of a cylinder is
\[
V=\pi r^2h.
\]
Alex’s cans have diameter 6 cm, so radius 3 cm, and height 12 cm:
\[
V_A=\pi(3^2)(12)=\pi(9)(12)=108\pi.
\]
Felicia’s cans have diameter 12 cm, so radius 6 cm, and height 6 cm:
\[
V_F=\pi(6^2)(6)=\pi(36)(6)=216\pi.
\]
The ratio of Alex’s can volume to Felicia’s can volume is
\[
108\pi:216\pi=108:216=1:2.
\]
ANSWER 9: B
Problem 10:
Let the number be \(N\). It leaves a remainder of 2 when divided by 3, 4, 5, and 6, so
\[
N-2
\]
is divisible by 3, 4, 5, and 6. Therefore, \(N-2\) must be a multiple of the least common multiple of 3, 4, 5, and 6.
Find the LCM:
\[
\operatorname{lcm}(3,4,5,6)=60.
\]
So
\[
N-2=60k
\]
for some positive integer \(k\), because we need \(N>2\).
The smallest possible value is when \(k=1\):
\[
N-2=60
\]
\[
N=62.
\]
This lies between 61 and 65.
ANSWER 10: D |
openrouter:anthropic/claude-opus-5 |
C | ✓ | showProblem 1: Sale price: 25% off means you pay 75%: 80 × 0.75 = 60 dollars. Add 10% tax: 60 × 1.10 = 66 dollars. (Choice C, 54, would come from subtracting 10%; choice D is correct. Note taking 25% off then adding 10% doesn't return to 80.) ANSWER 1: D Problem 2: Coastal road: 10 miles in 30 minutes, so 3 minutes per mile. Highway speed is 3 times as fast, so 1 minute per mile. Highway time: 50 miles × 1 minute/mile = 50 minutes. Total: 50 + 30 = 80 minutes. (Choice A forgets the coastal 30 minutes; choice D would come from using 3 min/mile on the highway incorrectly.) ANSWER 2: C Problem 3: The equation is 2^w · 3^x · 5^y · 7^z = 588. Factor 588 = 4 · 147 = 2² · 3 · 7². So w = 2, x = 1, y = 0, z = 2. Then 2w + 3x + 5y + 7z = 2(2) + 3(1) + 5(0) + 7(2) = 4 + 3 + 0 + 14 = 21. ANSWER 3: A Problem 4: Let Pedro's time be 0 (he's a reference). - Nico = +11 - Olympia = +3 (3 min behind Pedro) - Melina = Olympia + 2 = +5 - Luke = Olympia + 6 = +9 Order from first: Pedro (0), Olympia (3), Melina (5), Luke (9), Nico (11). Fourth place is Luke. ANSWER 4: A Problem 5: Total time away: 7:30 a.m. to 4:00 p.m. = 8 hours 30 minutes = 510 minutes. Time at school: classes 6 × 50 = 300, lunch 30, extra 2 hours = 120; total 450 minutes. Bus time = 510 − 450 = 60 minutes (both trips combined). ANSWER 5: B Problem 6: Let g = number of girls, b = g + 2 boys. Jelly beans used: b² + g² = 400 − 6 = 394. (g + 2)² + g² = 394 → 2g² + 4g + 4 = 394 → g² + 2g − 195 = 0 → (g + 15)(g − 13) = 0 → g = 13. So girls = 13, boys = 15; check 169 + 225 = 394 ✓. Total students = 28. ANSWER 6: B Problem 7: Four tires are on the road at any time, so total tire-miles = 4 × 30,000 = 120,000. Shared equally among 5 tires: 120,000 ÷ 5 = 24,000 miles each. (30,000 would be if no rotation; 6,000 is the rest time per tire, not use.) ANSWER 7: C Problem 8: Two-digit multiples of 7: 14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84, 91, 98. Digit sums: 5, 3, 10, 8, 6, 13, 11, 9, 7, 14, 12, 10, 17. Digit sum 10 occurs for 28 and 91. Sum: 28 + 91 = 119. ANSWER 8: A Problem 9: Alex: diameter 6 → radius 3, height 12: V = π(3²)(12) = 108π. Felicia: diameter 12 → radius 6, height 6: V = π(6²)(6) = 216π. Ratio = 108π : 216π = 1 : 2. (Doubling the radius quadruples volume, while halving height only halves it, so Felicia's is twice as big — not equal.) ANSWER 9: B Problem 10: A number leaving remainder 2 when divided by 3, 4, 5, and 6 must be 2 more than a common multiple of 3, 4, 5, 6. LCM(3, 4, 5, 6) = 60, so the smallest such number greater than 2 is 60 + 2 = 62. 62 lies between 61 and 65. ANSWER 10: D |
openrouter:openai/gpt-5.6-terra-pro |
C | ✓ | showProblem 1:
The dress was originally priced at \$80.
A 25% discount means the sale price is \(75\%\) of the original price:
\[
80 \times 0.75=60
\]
Then 10% tax is added:
\[
10\% \text{ of } 60 = 6
\]
So the total price is
\[
60+6=66
\]
A common mistake is to subtract 25% and add 10% of the original \$80, but the tax is added to the reduced sale price, not the original price.
\[
\boxed{66}
\]
ANSWER 1: D
Problem 2:
Anh drove 10 miles on the coastal road in 30 minutes.
Since 30 minutes is \(\frac12\) hour, his coastal-road speed was
\[
\frac{10\text{ miles}}{\frac12\text{ hour}}=20\text{ miles per hour}
\]
He drove three times as fast on the highway:
\[
3(20)=60\text{ miles per hour}
\]
The highway trip was 50 miles, so the highway driving time was
\[
\frac{50}{60}\text{ hour}=\frac56\text{ hour}
\]
Convert \(\frac56\) hour to minutes:
\[
\frac56\cdot 60=50\text{ minutes}
\]
His total driving time was
\[
30+50=80\text{ minutes}
\]
The answer is not 50 minutes, since that is only the highway time.
\[
\boxed{80}
\]
ANSWER 2: C
Problem 3:
We are told that
\[
2^w\cdot 3^x\cdot 5^y\cdot 7^z=588
\]
Factor 588 into primes:
\[
588=2\cdot 294=2^2\cdot 147=2^2\cdot 3\cdot 49
\]
Thus,
\[
588=2^2\cdot 3^1\cdot 5^0\cdot 7^2
\]
So
\[
w=2,\qquad x=1,\qquad y=0,\qquad z=2
\]
Now calculate:
\[
2w+3x+5y+7z
\]
\[
=2(2)+3(1)+5(0)+7(2)
\]
\[
=4+3+0+14=21
\]
The factor \(5^0\) is important: since 588 has no factor of 5, \(y=0\), not 1.
\[
\boxed{21}
\]
ANSWER 3: A
Problem 4:
We compare all runners’ finishing times relative to Pedro.
- Nico finished 11 minutes behind Pedro.
- Olympia finished 3 minutes behind Pedro.
- Olympia finished 2 minutes ahead of Melina, so Melina finished 2 minutes behind Olympia.
- Olympia finished 6 minutes ahead of Luke, so Luke finished 6 minutes behind Olympia.
Let Pedro finish at time 0.
Then:
\[
\begin{array}{c|c}
\text{Runner} & \text{Minutes behind Pedro} \\
\hline
\text{Pedro} & 0\\
\text{Olympia} & 3\\
\text{Melina} & 3+2=5\\
\text{Luke} & 3+6=9\\
\text{Nico} & 11
\end{array}
\]
Therefore, the order is:
1. Pedro
2. Olympia
3. Melina
4. Luke
5. Nico
So Luke finished fourth.
\[
\boxed{\text{Luke}}
\]
ANSWER 4: A
Problem 5:
Walter is at school from 7:30 a.m. until 4:00 p.m.
That is:
\[
8\text{ hours }30\text{ minutes}=510\text{ minutes}
\]
His school-day activities take:
- 6 classes of 50 minutes each:
\[
6\cdot 50=300\text{ minutes}
\]
- Lunch:
\[
30\text{ minutes}
\]
- Additional school time:
\[
2\text{ hours}=120\text{ minutes}
\]
Total time not spent on the bus:
\[
300+30+120=450\text{ minutes}
\]
Therefore, bus time is
\[
510-450=60\text{ minutes}
\]
This includes both the ride to school and the ride home.
\[
\boxed{60}
\]
ANSWER 5: B
Problem 6:
Let the number of girls be \(g\).
There are two more boys than girls, so the number of boys is
\[
g+2
\]
Each boy receives as many jelly beans as there are boys, so the boys receive
\[
(g+2)(g+2)=(g+2)^2
\]
jelly beans altogether.
Each girl receives \(g\) jelly beans, so the girls receive
\[
g^2
\]
jelly beans altogether.
Mrs. Awesome gave away
\[
400-6=394
\]
jelly beans. Therefore,
\[
g^2+(g+2)^2=394
\]
Expand:
\[
g^2+g^2+4g+4=394
\]
\[
2g^2+4g-390=0
\]
Divide by 2:
\[
g^2+2g-195=0
\]
Factor:
\[
(g+15)(g-13)=0
\]
So
\[
g=13
\]
since a number of girls cannot be negative.
Thus boys:
\[
13+2=15
\]
Total students:
\[
13+15=28
\]
\[
\boxed{28}
\]
ANSWER 6: B
Problem 7:
During the first 30,000 miles, the car always uses 4 tires on the road.
So the total number of tire-miles used is
\[
4\cdot 30{,}000=120{,}000
\]
There are 5 tires total, and they were rotated so each tire was used equally.
Therefore, each tire was used
\[
\frac{120{,}000}{5}=24{,}000
\]
miles.
It is not 30,000 miles because only four of the five tires are being driven on at any one time.
\[
\boxed{24{,}000}
\]
ANSWER 7: C
Problem 8:
We need two-digit multiples of 7 whose digits add to 10.
The two-digit multiples of 7 are:
\[
14,21,28,35,42,49,56,63,70,77,84,91,98
\]
Check digit sums:
\[
28:\quad 2+8=10
\]
\[
91:\quad 9+1=10
\]
These are the only two.
Their sum is
\[
28+91=119
\]
\[
\boxed{119}
\]
ANSWER 8: A
Problem 9:
The volume of a cylinder is
\[
V=\pi r^2h
\]
For Alex’s can:
- Diameter \(=6\), so radius \(=3\)
- Height \(=12\)
\[
V_A=\pi(3)^2(12)=108\pi
\]
For Felicia’s can:
- Diameter \(=12\), so radius \(=6\)
- Height \(=6\)
\[
V_F=\pi(6)^2(6)=216\pi
\]
The ratio of Alex’s volume to Felicia’s volume is
\[
108\pi:216\pi
\]
Divide both parts by \(108\pi\):
\[
1:2
\]
Although Alex’s can is twice as tall, Felicia’s radius is twice as large, and radius is squared in the volume formula.
\[
\boxed{1:2}
\]
ANSWER 9: B
Problem 10:
We seek the smallest number greater than 2 that leaves remainder 2 when divided by 3, 4, 5, and 6.
If the number is \(n\), then \(n-2\) must be divisible by all of
\[
3,\ 4,\ 5,\ 6
\]
The least common multiple is
\[
\operatorname{lcm}(3,4,5,6)=60
\]
So the smallest possible value of \(n-2\) is 60:
\[
n-2=60
\]
\[
n=62
\]
The number 62 lies between 61 and 65.
Indeed:
\[
62\div 3,\ 62\div 4,\ 62\div 5,\ 62\div 6
\]
all leave remainder 2.
\[
\boxed{61\text{ and }65}
\]
ANSWER 10: D |
There are many two-digit multiples of 7, but only two of them have a digit sum of 10. The sum of these two multiples of 7 is
| Model | Pick | ✓/✗ | Reasoning |
|---|---|---|---|
openrouter:meta/muse-spark-1.3 |
A | ✓ | showProblem 1: We are asked for the final price after a discount and then tax. Original price is 80 dollars. 25% off means pay 100% - 25% = 75% of original. Sale price = 0.75 × 80 = 60 dollars. Tempting mistake: subtract 25 dollars to get 55. No, 25% means percent, not dollars. Then 10% tax is added to the sale price, not the original price. Tax = 10% of 60 = 6 dollars. Total = 60 + 6 = 66 dollars. Equivalently 1.10 × 60 = 66. Check: A 45 is far too low. B 52 would be 35% off total. C 54 would be adding tax incorrectly. E 68 would be adding 10% of 80. ANSWER 1: D Problem 2: We need total time = time on coastal road + time on highway. Given time on coastal road = 30 minutes for 10 miles. Let coastal speed = v. Then v = 10 miles / 30 min. Highway speed is three times as fast: 3v. Highway distance is 50 miles. Time = distance / speed, so: Highway time = 50 / (3v). From coastal: 10 / v = 30, so 1/v = 3 min per mile. Thus highway time = 50 / 3 × (1/v) = 50/3 × 3 = 50 minutes. Total = 30 + 50 = 80 minutes. Alternative check: Highway is 5 times distance but 3 times speed, so takes 5/3 as long as coastal: 30 × 5/3 = 50. ANSWER 2: C Problem 3: We are told w,x,y,z are whole numbers, so 0,1,2,... And 2^w · 3^x · 5^y · 7^z = 588. Find 2w + 3x + 5y + 7z. Factor 588 into primes. 588 = 58.8 × 10, but do integer: 588 = 2 × 294 = 2 × 2 × 147 = 4 × 147. 147 = 3 × 49 = 3 × 7 × 7. So 588 = 2^2 × 3^1 × 5^0 × 7^2. By uniqueness of prime factorization, exponents must match: w = 2, x = 1, y = 0, z = 2. Note y=0 is allowed because whole numbers include 0, and 5^0 = 1. Now compute linear expression: 2w + 3x + 5y + 7z = 2×2 + 3×1 + 5×0 + 7×2 = 4 + 3 + 0 + 14 = 21. ANSWER 3: A Problem 4: Order the five finishers by time behind Pedro. Let Pedro's time be P. Nico finished 11 minutes behind Pedro: N = P+11. Olympia finished 3 minutes behind Pedro: O = P+3. Olympia finished 2 minutes ahead of Melina: So Melina is 2 minutes behind Olympia: M = O+2 = P+5. Olympia finished 6 minutes ahead of Luke: So Luke is 6 minutes behind Olympia: L = O+6 = P+9. Order by increasing time: Pedro at P+0 — 1st Olympia at P+3 — 2nd Melina at P+5 — 3rd Luke at P+9 — 4th Nico at P+11 — 5th So fourth is Luke. ANSWER 4: A Problem 5: Total elapsed time from boarding morning bus to arriving home. From 7:30 a.m. to 4:00 p.m. = 8.5 hours = 8×60 + 30 = 510 minutes. Time at school: 6 classes × 50 min = 300 min. Lunch 30 min. Additional 2 hours = 120 min. Total school = 300 + 30 + 120 = 450 min. Bus time (morning + afternoon) = total elapsed - school time = 510 - 450 = 60 minutes. Tempting error: miscount 7:30 to 4:00 as 8 hours. ANSWER 5: B Problem 6: Let g = number of girls. Then number of boys b = g+2. Each boy gets b beans, so boys total = b × b = b^2. Each girl gets g beans, so girls total = g × g = g^2. Beans used = 400 - 6 left = 394. So b^2 + g^2 = 394. Substitute: (g+2)^2 + g^2 = 394 g^2 + 4g + 4 + g^2 = 394 2g^2 + 4g - 390 = 0 Divide 2: g^2 + 2g - 195 = 0. Factor 195 = 13 × 15, differing by 2: (g+15)(g-13)=0. Positive solution g = 13. Then b = 15. Total students = 13+15 = 28. Check: 15^2+13^2 =225+169=394 correct. ANSWER 6: B Problem 7: The car travels 30,000 miles. At any moment exactly 4 tires are on the road carrying it. Total tire-miles delivered = 4 tires × 30,000 miles = 120,000 tire-miles. This wear is shared equally among 5 tires by rotation. Per tire = 120,000 / 5 = 24,000 miles. Tempting wrong: 30,000/5 = 6,000 ignores that 4 tires are used at once. 30,000 would mean no rotation. ANSWER 7: C Problem 8: List two-digit multiples of 7: 14,21,28,35,42,49,56,63,70,77,84,91,98. Compute digit sums: 1+4=5, 2+1=3, 2+8=10, 3+5=8, 4+2=6, 4+9=13, 5+6=11, 6+3=9, 7+0=7, 7+7=14, 8+4=12, 9+1=10, 9+8=17. Only two have sum 10: 28 and 91. Their sum = 28+91 = 119. ANSWER 8: A Problem 9: Volume of cylinder = π r^2 h, where r = diameter/2. Alex: diameter 6, so r=3. height 12. V_A = π × 3^2 × 12 = π × 9 × 12 = 108π. Felicia: diameter 12, so r=6. height 6. V_F = π × 6^2 × 6 = π × 36 × 6 = 216π. Ratio V_A : V_F = 108π : 216π = 108:216 = 1:2. Note volume scales with square of radius, so doubling diameter quadruples base area, outweighing halving height. ANSWER 9: B Problem 10: We need N > 2 with N ≡ 2 mod 3, mod 4, mod 5, mod 6. So N-2 is divisible by each of 3,4,5,6. N-2 must be a common multiple of 3,4,5,6. LCM(3,4,5,6): 4=2^2, 6=2×3, so LCM = 2^2 × 3 × 5 = 60. Positive multiples: 60,120,... N=2 gives N-2=0 which works but is excluded by >2. Next smallest is N-2 = 60, so N = 62. 62 is between 61 and 65. Check: 62 ÷ 3 =20 rem 2, ÷4=15 rem 2, etc. ANSWER 10: D |
openrouter:google/gemini-3.8-flash |
A | ✓ | showProblem 1:
**Restatement and Setup:**
We are given an item with an original price of $\$80$. It is discounted by $25\%$, and then a $10\%$ sales tax is applied to this discounted sale price. We need to find the final total selling price.
**Step-by-step computation:**
1. Calculate the discount:
$$\text{Discount} = 25\% \text{ of } \$80 = 0.25 \times 80 = \$20$$
2. Calculate the sale price:
$$\text{Sale Price} = \$80 - \$20 = \$60$$
*(Alternatively, the sale price is $75\%$ of $\$80$: $0.75 \times 80 = \$60$.)*
3. Calculate the tax on the sale price:
$$\text{Tax} = 10\% \text{ of } \$60 = 0.10 \times 60 = \$6$$
4. Calculate the total price:
$$\text{Total Price} = \$60 + \$6 = \$66$$
**Ruling out wrong choices:**
- Choice A ($\$45$) results from incorrectly subtracting both $25\%$ and $10\%$ from the original price, or similar errors.
- Choice B ($\$52$) and Choice C ($\$54$) are too low.
- Choice E ($\$68$) might occur if the tax were incorrectly computed on the original $\$80$ price ($80 \times 0.10 = \$8$) and added to $\$60$.
ANSWER 1: D
---
Problem 2:
**Restatement and Setup:**
Anh drives on two segments:
- Coastal access road: distance $d_c = 10$ miles, time $t_c = 30$ minutes.
- Highway: distance $d_h = 50$ miles.
He drives three times as fast on the highway as on the coastal access road ($v_h = 3 v_c$). We need to find the total time in minutes for the entire trip.
**Step-by-step computation:**
1. Find the speed on the coastal road:
Anh drives $10$ miles in $30$ minutes ($0.5$ hours).
$$v_c = \frac{10\text{ miles}}{0.5\text{ hours}} = 20\text{ mph}$$
2. Find the speed on the highway:
$$v_h = 3 \times v_c = 3 \times 20\text{ mph} = 60\text{ mph} = 1\text{ mile per minute}$$
3. Find the time spent on the highway:
$$t_h = \frac{50\text{ miles}}{1\text{ mile per minute}} = 50\text{ minutes}$$
4. Find the total trip time:
$$\text{Total time} = t_c + t_h = 30\text{ minutes} + 50\text{ minutes} = 80\text{ minutes}$$
**Ruling out wrong choices:**
- Choice A ($50$) is just the time on the highway.
- Choices B ($70$), D ($90$), and E ($100$) arise from miscalculating the highway speed ratio or mixing up minutes and hours.
ANSWER 2: C
---
Problem 3:
**Restatement and Setup:**
Given whole numbers (non-negative integers) $w, x, y, z$ such that:
$$2^w \cdot 3^x \cdot 5^y \cdot 7^z = 588$$
We need to find the value of $2w + 3x + 5y + 7z$.
**Step-by-step computation:**
1. Find the prime factorization of $588$:
$$588 = 2 \times 294 = 2 \times 2 \times 147 = 4 \times 3 \times 49 = 2^2 \times 3^1 \times 7^2$$
2. Matching the prime factors with $2^w \cdot 3^x \cdot 5^y \cdot 7^z$:
- $w = 2$
- $x = 1$
- $y = 0$ (since $5$ is not a factor of $588$)
- $z = 2$
3. Compute the required expression $2w + 3x + 5y + 7z$:
$$2(2) + 3(1) + 5(0) + 7(2) = 4 + 3 + 0 + 14 = 21$$
**Ruling out wrong choices:**
- If one mistakenly sets $y=1$, the sum would be $21 + 5 = 26$ (close to 25 or 27).
- Choices B, C, D, and E do not match the evaluated sum of $21$.
ANSWER 3: A
---
Problem 4:
**Restatement and Setup:**
Five runners (Luke, Melina, Nico, Olympia, Pedro) finished a race. We are given relative finish times:
- Nico finished $11$ minutes behind Pedro.
- Olympia finished $3$ minutes behind Pedro.
- Olympia finished $2$ minutes ahead of Melina.
- Olympia finished $6$ minutes ahead of Luke.
We need to determine who finished in fourth place.
**Step-by-step computation:**
Let Pedro's finish time be $t=0$ minutes (the earliest/winner).
- Pedro finishes at $0$ minutes.
- Olympia finished $3$ minutes behind Pedro $\implies$ Olympia finishes at $0 + 3 = 3$ minutes.
- Olympia finished $2$ minutes ahead of Melina $\implies$ Melina finishes $2$ minutes after Olympia $\implies 3 + 2 = 5$ minutes.
- Olympia finished $6$ minutes ahead of Luke $\implies$ Luke finishes $6$ minutes after Olympia $\implies 3 + 6 = 9$ minutes.
- Nico finished $11$ minutes behind Pedro $\implies$ Nico finishes at $0 + 11 = 11$ minutes.
Listing the runners in order of finish:
1. Pedro ($0$ min)
2. Olympia ($3$ min)
3. Melina ($5$ min)
4. Luke ($9$ min)
5. Nico ($11$ min)
Thus, Luke finished fourth.
**Ruling out wrong choices:**
- Pedro was 1st, Olympia was 2nd, Melina was 3rd, and Nico was 5th (last).
ANSWER 4: A
---
Problem 5:
**Restatement and Setup:**
Walter boards the bus at 7:30 a.m. and arrives home from the bus at 4:00 p.m.
During the day, he spends time on the bus (both ways) and at school.
School activities consist of:
- $6$ classes of $50$ minutes each
- $30$ minutes for lunch
- $2$ hours of additional time
We need to find the total time Walter spent on the bus.
**Step-by-step computation:**
1. Calculate total elapsed time between leaving home and returning:
- From 7:30 a.m. to 12:00 p.m. is $4$ hours and $30$ minutes ($4.5$ hours).
- From 12:00 p.m. to 4:00 p.m. is $4$ hours.
- Total elapsed time = $8$ hours and $30$ minutes $= 8 \times 60 + 30 = 510$ minutes.
2. Calculate total time spent on school activities:
- Classes: $6 \times 50\text{ minutes} = 300\text{ minutes}$
- Lunch: $30\text{ minutes}$
- Additional time: $2\text{ hours} = 120\text{ minutes}$
- Total school time $= 300 + 30 + 120 = 450\text{ minutes}$.
3. Calculate time spent on the bus:
$$\text{Bus time} = \text{Total time} - \text{School time} = 510 - 450 = 60\text{ minutes}$$
**Ruling out wrong choices:**
- 30 minutes assumes only a one-way trip or forgets additional school time.
- 75, 90, 120 minutes result from miscounting the elapsed time or forgetting the 30-minute lunch.
ANSWER 5: B
---
Problem 6:
**Restatement and Setup:**
Let $b$ be the number of boys and $g$ be the number of girls.
- Each boy receives $b$ jelly beans (total $b^2$).
- Each girl receives $g$ jelly beans (total $g^2$).
- Total jelly beans distributed: $400 - 6 = 394$.
- There are two more boys than girls: $b = g + 2$.
We need to find the total number of students in the class, which is $b + g$.
**Step-by-step com |
openrouter:~z-ai/glm-latest |
A | ✓ | show# Problem 1: **What is asked:** Find the final price after a 25% discount on $80, followed by 10% tax on the *sale price*. **Step 1 — Compute the sale price (25% off):** Discount = 25% of 80 = 0.25 × 80 = $20. Sale price = 80 − 20 = **$60**. **Step 2 — Add 10% tax to the sale price:** Tax = 10% of 60 = $6. Total = 60 + 6 = **$66**. **Rule out wrong answers:** - $52 (B) comes from wrongly taking 10% off the *original* price (60 − 8), but tax is added, not discounted. - $54 (C) comes from adding discounts: 80 × 0.75 × 0.9 — but tax increases the price. - The correct sequence is 80 → 60 → 66. ANSWER 1: D # Problem 2: **What is asked:** Find the total driving time in minutes. **Step 1 — Coastal road speed:** Anh drove 10 miles in 30 minutes (= 0.5 hour). Speed = 10 ÷ 0.5 = **20 mph**. **Step 2 — Highway speed:** He drove 3 times as fast: 3 × 20 = **60 mph**. **Step 3 — Highway time:** Time = distance ÷ speed = 50 ÷ 60 = 5/6 hour = **50 minutes**. **Step 4 — Total time:** 30 + 50 = **80 minutes**. **Rule out wrong answers:** - 90 (D) would result from wrongly assuming equal speeds (30 min + 60 min); but the highway was faster, so its time is *less* than 60 minutes. Only 80 fits. ANSWER 2: C # Problem 3: **What is asked:** Given 2^w · 3^x · 5^y · 7^z = 588, find 2w + 3x + 5y + 7z. **Step 1 — Factor 588:** 588 = 4 × 147 = 4 × 3 × 49 = 2² × 3 × 7². **Step 2 — Read off exponents:** 588 = 2² · 3¹ · 5⁰ · 7², so w = 2, x = 1, y = 0, z = 2. **Step 3 — Compute the expression:** 2w + 3x + 5y + 7z = 2(2) + 3(1) + 5(0) + 7(2) = 4 + 3 + 0 + 14 = **21**. **Rule out wrong answers:** 35 (D) or 56 (E) would come from confusing the coefficients 2,3,5,7 with the bases; note 588 is not divisible by 5, forcing y = 0. ANSWER 3: A # Problem 4: **What is asked:** Determine which runner finished fourth (in order of finishing time). **Step 1 — Set Pedro's time as P (a reference).** Then: - Nico finished 11 minutes behind Pedro: Nico = P + 11. - Olympia finished 3 minutes behind Pedro: Olympia = P + 3. - Olympia finished 2 minutes ahead of Melina, so Melina = P + 3 + 2 = P + 5. - Olympia finished 6 minutes ahead of Luke, so Luke = P + 3 + 6 = P + 9. **Step 2 — Order from fastest to slowest:** Pedro (P), Olympia (P+3), Melina (P+5), Luke (P+9), Nico (P+11). **Step 3 — Fourth place** is **Luke**. **Rule out wrong answers:** Nico (C) is last (5th), Pedro (E) is first; a common error is swapping Luke and Melina — but Luke = P+9 is behind Melina = P+5. ANSWER 4: A # Problem 5: **What is asked:** Total time Walter spent on the bus (both ways). **Step 1 — Total elapsed time from 7:30 a.m. to 4:00 p.m.:** That is 8 hours 30 minutes = 510 minutes. **Step 2 — Time accounted for at school:** - Classes: 6 × 50 = 300 minutes - Lunch: 30 minutes - Additional time: 2 hours = 120 minutes - Total school time: 300 + 30 + 120 = 450 minutes. **Step 3 — Bus time:** 510 − 450 = **60 minutes**. **Rule out wrong answers:** 90 (D) would ignore lunch or additional time; 30 (A) would count only one bus ride — but the round trip must be 60 minutes total. ANSWER 5: B # Problem 6: **What is asked:** Find the total number of students. **Step 1 — Set up equations.** Let g = number of girls, b = number of boys. Each boy gets b beans (b boys), each girl gets g beans (g girls): b² + g² = 400 − 6 = 394, and b = g + 2. **Step 2 — Substitute and solve:** (g+2)² + g² = 394 g² + 4g + 4 + g² = 394 2g² + 4g − 390 = 0 g² + 2g − 195 = 0 (g + 15)(g − 13) = 0 → g = 13 (reject −15). **Step 3 — Find the total:** Boys: b = 13 + 2 = 15. Total students = 15 + 13 = **28**. **Check:** 15² + 13² = 225 + 169 = 394 = 400 − 6. ✓ ANSWER 6: B # Problem 7: **What is asked:** Miles each of the 5 tires was used over 30,000 miles. **Step 1 — Total tire-miles used:** At any moment the car uses 4 tires. Over 30,000 miles, total tire-miles = 4 × 30,000 = 120,000. **Step 2 — Split equally among 5 tires:** 120,000 ÷ 5 = **24,000 miles** each. **Rule out wrong answers:** 30,000 (D) is wrong because no single tire can be used the whole time when 5 tires share the work; 6,000 (A) and 7,500 (B) wrongly divide by the wrong quantity (e.g., 30,000 ÷ 5 or ÷ 4). ANSWER 7: C # Problem 8: **What is asked:** Sum of the two two-digit multiples of 7 whose digits sum to 10. **Step 1 — List two-digit multiples of 7 and digit sums:** 14 (5), 21 (3), **28 (10)** ✓, 35 (8), 42 (6), 49 (13), 56 (11), 63 (9), 70 (7), 77 (14), 84 (12), **91 (10)** ✓, 98 (17). **Step 2 — Identify the two qualifying numbers:** 28 and 91. **Step 3 — Sum:** 28 + 91 = **119**. **Rule out wrong answers:** 126 (B) is 63 + 63 — impossible since numbers are distinct; 140 (D) might come from 28 + 112 (but 112 is three digits). ANSWER 8: A # Problem 9: **What is asked:** Ratio of Alex's can volume to Felicia's can volume. **Step 1 — Volume formula:** V = πr²h. **Step 2 — Alex's can:** diameter 6 → radius 3; height 12. V_A = π(3)²(12) = 108π. **Step 3 — Felicia's can:** diameter 12 → radius 6; height 6. V_F = π(6)²(6) = 216π. **Step 4 — Ratio:** V_A : V_F = 108π : 216π = **1 : 2**. **Rule out wrong answers:** 1:1 (C) is the tempting "swapped dimensions" intuition, but volume depends on the *square* of the radius, so doubling the radius quadruples that factor while halving the height only halves — net effect is Felicia's can is twice as big. ANSWER 9: B # Problem 10: **What is asked:** Find the smallest number > 2 that leaves remainder 2 when divided by 3, 4, 5, and 6, and identify the interval containing it. **Step 1 — Interpret the condition:** N − 2 must be divisible by 3, 4, 5, and 6, i.e., N − 2 is a multiple of LCM(3, 4, 5, 6). **Step 2 — Compute the LCM:** LCM(3,4,5,6) = 60 (since 60 is divisible by 3, 4, 5, and 6). **Step 3 — Candidates:** N = 60k + 2 for whole numbers k: N = 2, 62, 122, ... The smallest *greater than 2* is **62**. **Step 4 — Locate 62:** It lies between **61 and 65**. **Rule out wrong answers:** 42 + 2 = 44 is a common error (using 42, the LCM of only |
openrouter:qwen/qwen3.8-27b |
A | ✓ | showProblem 1:
The dress is originally priced at \$80. A 25% discount means the sale price is
\[
80(1-0.25)=80(0.75)=60.
\]
Then 10% tax is added to the sale price:
\[
60(1+0.10)=60(1.10)=66.
\]
So the total selling price is \$66.
ANSWER 1: D
Problem 2:
Anh drove 10 miles on the coastal road in 30 minutes, so his coastal-road speed was
\[
\frac{10\text{ miles}}{30\text{ minutes}}.
\]
He drove three times as fast on the highway. Therefore, for the same distance, the highway time would be one-third as long.
For 50 miles on the highway, if he had driven at coastal-road speed, it would take
\[
30 \times \frac{50}{10}=150
\]
minutes. But because he drove three times as fast on the highway, the actual highway time is
\[
\frac{150}{3}=50
\]
minutes.
The coastal road took 30 minutes, so the total trip time was
\[
30+50=80
\]
minutes.
ANSWER 2: C
Problem 3:
The equation should be read as
\[
2^w \cdot 3^x \cdot 5^y \cdot 7^z = 588.
\]
Factor 588:
\[
588=2\cdot 294=2^2\cdot 147=2^2\cdot 3\cdot 49=2^2\cdot 3^1\cdot 7^2.
\]
There is no factor of 5, so \(y=0\). Comparing prime exponents gives
\[
w=2,\qquad x=1,\qquad y=0,\qquad z=2.
\]
Now compute
\[
2w+3x+5y+7z=2(2)+3(1)+5(0)+7(2).
\]
\[
=4+3+0+14=21.
\]
ANSWER 3: A
Problem 4:
Let Pedro’s finishing time be \(P\). In a race, a smaller time means finishing earlier.
- Nico finished 11 minutes behind Pedro, so Nico’s time is
\[
P+11.
\]
- Olympia finished 3 minutes behind Pedro, so Olympia’s time is
\[
P+3.
\]
- Olympia finished 2 minutes ahead of Melina, so Melina’s time is
\[
(P+3)+2=P+5.
\]
- Olympia finished 6 minutes ahead of Luke, so Luke’s time is
\[
(P+3)+6=P+9.
\]
Now order the runners from first to last by increasing time:
\[
P,\quad P+3,\quad P+5,\quad P+9,\quad P+11.
\]
That is:
1. Pedro
2. Olympia
3. Melina
4. Luke
5. Nico
So the fourth runner was Luke.
ANSWER 4: A
Problem 5:
From 7:30 a.m. to 4:00 p.m. is 8 hours and 30 minutes:
\[
8(60)+30=480+30=510
\]
minutes.
Walter’s time in school not spent on the bus is:
- 6 classes of 50 minutes each:
\[
6(50)=300
\]
minutes;
- lunch: 30 minutes;
- additional time: 2 hours = 120 minutes.
Total non-bus time:
\[
300+30+120=450
\]
minutes.
So his total bus time was
\[
510-450=60
\]
minutes.
ANSWER 5: B
Problem 6:
Let the number of girls be \(g\). Since there were two more boys than girls, the number of boys is
\[
g+2.
\]
Mrs. Awesome gave each boy as many jelly beans as there were boys, so the boys received
\[
(g+2)^2
\]
jelly beans total. Each girl received as many as there were girls, so the girls received
\[
g^2
\]
jelly beans total.
She had 400 jelly beans and 6 left, so she gave away
\[
400-6=394.
\]
Thus,
\[
(g+2)^2+g^2=394.
\]
Expand:
\[
g^2+4g+4+g^2=394
\]
\[
2g^2+4g+4=394
\]
\[
2g^2+4g-390=0
\]
Divide by 2:
\[
g^2+2g-195=0.
\]
Factor:
\[
(g+15)(g-13)=0.
\]
Since \(g\) must be positive,
\[
g=13.
\]
Then the number of boys is
\[
13+2=15.
\]
The total number of students is
\[
13+15=28.
\]
ANSWER 6: B
Problem 7:
During the first 30,000 miles, the car was always using 4 tires at once. Therefore, the total “tire-miles” used is
\[
4 \times 30{,}000=120{,}000.
\]
There are 5 tires total, and they were all used the same number of miles. So each tire was used for
\[
\frac{120{,}000}{5}=24{,}000
\]
miles.
ANSWER 7: C
Problem 8:
We need two-digit multiples of 7 whose digits sum to 10.
The two-digit multiples of 7 are:
\[
14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84, 91, 98.
\]
Check digit sums:
\[
14: 1+4=5
\]
\[
21: 2+1=3
\]
\[
28: 2+8=10
\]
\[
35: 3+5=8
\]
\[
42: 4+2=6
\]
\[
49: 4+9=13
\]
\[
56: 5+6=11
\]
\[
63: 6+3=9
\]
\[
70: 7+0=7
\]
\[
77: 7+7=14
\]
\[
84: 8+4=12
\]
\[
91: 9+1=10
\]
\[
98: 9+8=17
\]
The only two are 28 and 91. Their sum is
\[
28+91=119.
\]
ANSWER 8: A
Problem 9:
The volume of a cylinder is
\[
V=\pi r^2h.
\]
Alex’s cans have diameter 6 cm, so radius 3 cm, and height 12 cm:
\[
V_A=\pi(3^2)(12)=\pi(9)(12)=108\pi.
\]
Felicia’s cans have diameter 12 cm, so radius 6 cm, and height 6 cm:
\[
V_F=\pi(6^2)(6)=\pi(36)(6)=216\pi.
\]
The ratio of Alex’s can volume to Felicia’s can volume is
\[
108\pi:216\pi=108:216=1:2.
\]
ANSWER 9: B
Problem 10:
Let the number be \(N\). It leaves a remainder of 2 when divided by 3, 4, 5, and 6, so
\[
N-2
\]
is divisible by 3, 4, 5, and 6. Therefore, \(N-2\) must be a multiple of the least common multiple of 3, 4, 5, and 6.
Find the LCM:
\[
\operatorname{lcm}(3,4,5,6)=60.
\]
So
\[
N-2=60k
\]
for some positive integer \(k\), because we need \(N>2\).
The smallest possible value is when \(k=1\):
\[
N-2=60
\]
\[
N=62.
\]
This lies between 61 and 65.
ANSWER 10: D |
openrouter:anthropic/claude-opus-5 |
A | ✓ | showProblem 1: Sale price: 25% off means you pay 75%: 80 × 0.75 = 60 dollars. Add 10% tax: 60 × 1.10 = 66 dollars. (Choice C, 54, would come from subtracting 10%; choice D is correct. Note taking 25% off then adding 10% doesn't return to 80.) ANSWER 1: D Problem 2: Coastal road: 10 miles in 30 minutes, so 3 minutes per mile. Highway speed is 3 times as fast, so 1 minute per mile. Highway time: 50 miles × 1 minute/mile = 50 minutes. Total: 50 + 30 = 80 minutes. (Choice A forgets the coastal 30 minutes; choice D would come from using 3 min/mile on the highway incorrectly.) ANSWER 2: C Problem 3: The equation is 2^w · 3^x · 5^y · 7^z = 588. Factor 588 = 4 · 147 = 2² · 3 · 7². So w = 2, x = 1, y = 0, z = 2. Then 2w + 3x + 5y + 7z = 2(2) + 3(1) + 5(0) + 7(2) = 4 + 3 + 0 + 14 = 21. ANSWER 3: A Problem 4: Let Pedro's time be 0 (he's a reference). - Nico = +11 - Olympia = +3 (3 min behind Pedro) - Melina = Olympia + 2 = +5 - Luke = Olympia + 6 = +9 Order from first: Pedro (0), Olympia (3), Melina (5), Luke (9), Nico (11). Fourth place is Luke. ANSWER 4: A Problem 5: Total time away: 7:30 a.m. to 4:00 p.m. = 8 hours 30 minutes = 510 minutes. Time at school: classes 6 × 50 = 300, lunch 30, extra 2 hours = 120; total 450 minutes. Bus time = 510 − 450 = 60 minutes (both trips combined). ANSWER 5: B Problem 6: Let g = number of girls, b = g + 2 boys. Jelly beans used: b² + g² = 400 − 6 = 394. (g + 2)² + g² = 394 → 2g² + 4g + 4 = 394 → g² + 2g − 195 = 0 → (g + 15)(g − 13) = 0 → g = 13. So girls = 13, boys = 15; check 169 + 225 = 394 ✓. Total students = 28. ANSWER 6: B Problem 7: Four tires are on the road at any time, so total tire-miles = 4 × 30,000 = 120,000. Shared equally among 5 tires: 120,000 ÷ 5 = 24,000 miles each. (30,000 would be if no rotation; 6,000 is the rest time per tire, not use.) ANSWER 7: C Problem 8: Two-digit multiples of 7: 14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84, 91, 98. Digit sums: 5, 3, 10, 8, 6, 13, 11, 9, 7, 14, 12, 10, 17. Digit sum 10 occurs for 28 and 91. Sum: 28 + 91 = 119. ANSWER 8: A Problem 9: Alex: diameter 6 → radius 3, height 12: V = π(3²)(12) = 108π. Felicia: diameter 12 → radius 6, height 6: V = π(6²)(6) = 216π. Ratio = 108π : 216π = 1 : 2. (Doubling the radius quadruples volume, while halving height only halves it, so Felicia's is twice as big — not equal.) ANSWER 9: B Problem 10: A number leaving remainder 2 when divided by 3, 4, 5, and 6 must be 2 more than a common multiple of 3, 4, 5, 6. LCM(3, 4, 5, 6) = 60, so the smallest such number greater than 2 is 60 + 2 = 62. 62 lies between 61 and 65. ANSWER 10: D |
openrouter:openai/gpt-5.6-terra-pro |
A | ✓ | showProblem 1:
The dress was originally priced at \$80.
A 25% discount means the sale price is \(75\%\) of the original price:
\[
80 \times 0.75=60
\]
Then 10% tax is added:
\[
10\% \text{ of } 60 = 6
\]
So the total price is
\[
60+6=66
\]
A common mistake is to subtract 25% and add 10% of the original \$80, but the tax is added to the reduced sale price, not the original price.
\[
\boxed{66}
\]
ANSWER 1: D
Problem 2:
Anh drove 10 miles on the coastal road in 30 minutes.
Since 30 minutes is \(\frac12\) hour, his coastal-road speed was
\[
\frac{10\text{ miles}}{\frac12\text{ hour}}=20\text{ miles per hour}
\]
He drove three times as fast on the highway:
\[
3(20)=60\text{ miles per hour}
\]
The highway trip was 50 miles, so the highway driving time was
\[
\frac{50}{60}\text{ hour}=\frac56\text{ hour}
\]
Convert \(\frac56\) hour to minutes:
\[
\frac56\cdot 60=50\text{ minutes}
\]
His total driving time was
\[
30+50=80\text{ minutes}
\]
The answer is not 50 minutes, since that is only the highway time.
\[
\boxed{80}
\]
ANSWER 2: C
Problem 3:
We are told that
\[
2^w\cdot 3^x\cdot 5^y\cdot 7^z=588
\]
Factor 588 into primes:
\[
588=2\cdot 294=2^2\cdot 147=2^2\cdot 3\cdot 49
\]
Thus,
\[
588=2^2\cdot 3^1\cdot 5^0\cdot 7^2
\]
So
\[
w=2,\qquad x=1,\qquad y=0,\qquad z=2
\]
Now calculate:
\[
2w+3x+5y+7z
\]
\[
=2(2)+3(1)+5(0)+7(2)
\]
\[
=4+3+0+14=21
\]
The factor \(5^0\) is important: since 588 has no factor of 5, \(y=0\), not 1.
\[
\boxed{21}
\]
ANSWER 3: A
Problem 4:
We compare all runners’ finishing times relative to Pedro.
- Nico finished 11 minutes behind Pedro.
- Olympia finished 3 minutes behind Pedro.
- Olympia finished 2 minutes ahead of Melina, so Melina finished 2 minutes behind Olympia.
- Olympia finished 6 minutes ahead of Luke, so Luke finished 6 minutes behind Olympia.
Let Pedro finish at time 0.
Then:
\[
\begin{array}{c|c}
\text{Runner} & \text{Minutes behind Pedro} \\
\hline
\text{Pedro} & 0\\
\text{Olympia} & 3\\
\text{Melina} & 3+2=5\\
\text{Luke} & 3+6=9\\
\text{Nico} & 11
\end{array}
\]
Therefore, the order is:
1. Pedro
2. Olympia
3. Melina
4. Luke
5. Nico
So Luke finished fourth.
\[
\boxed{\text{Luke}}
\]
ANSWER 4: A
Problem 5:
Walter is at school from 7:30 a.m. until 4:00 p.m.
That is:
\[
8\text{ hours }30\text{ minutes}=510\text{ minutes}
\]
His school-day activities take:
- 6 classes of 50 minutes each:
\[
6\cdot 50=300\text{ minutes}
\]
- Lunch:
\[
30\text{ minutes}
\]
- Additional school time:
\[
2\text{ hours}=120\text{ minutes}
\]
Total time not spent on the bus:
\[
300+30+120=450\text{ minutes}
\]
Therefore, bus time is
\[
510-450=60\text{ minutes}
\]
This includes both the ride to school and the ride home.
\[
\boxed{60}
\]
ANSWER 5: B
Problem 6:
Let the number of girls be \(g\).
There are two more boys than girls, so the number of boys is
\[
g+2
\]
Each boy receives as many jelly beans as there are boys, so the boys receive
\[
(g+2)(g+2)=(g+2)^2
\]
jelly beans altogether.
Each girl receives \(g\) jelly beans, so the girls receive
\[
g^2
\]
jelly beans altogether.
Mrs. Awesome gave away
\[
400-6=394
\]
jelly beans. Therefore,
\[
g^2+(g+2)^2=394
\]
Expand:
\[
g^2+g^2+4g+4=394
\]
\[
2g^2+4g-390=0
\]
Divide by 2:
\[
g^2+2g-195=0
\]
Factor:
\[
(g+15)(g-13)=0
\]
So
\[
g=13
\]
since a number of girls cannot be negative.
Thus boys:
\[
13+2=15
\]
Total students:
\[
13+15=28
\]
\[
\boxed{28}
\]
ANSWER 6: B
Problem 7:
During the first 30,000 miles, the car always uses 4 tires on the road.
So the total number of tire-miles used is
\[
4\cdot 30{,}000=120{,}000
\]
There are 5 tires total, and they were rotated so each tire was used equally.
Therefore, each tire was used
\[
\frac{120{,}000}{5}=24{,}000
\]
miles.
It is not 30,000 miles because only four of the five tires are being driven on at any one time.
\[
\boxed{24{,}000}
\]
ANSWER 7: C
Problem 8:
We need two-digit multiples of 7 whose digits add to 10.
The two-digit multiples of 7 are:
\[
14,21,28,35,42,49,56,63,70,77,84,91,98
\]
Check digit sums:
\[
28:\quad 2+8=10
\]
\[
91:\quad 9+1=10
\]
These are the only two.
Their sum is
\[
28+91=119
\]
\[
\boxed{119}
\]
ANSWER 8: A
Problem 9:
The volume of a cylinder is
\[
V=\pi r^2h
\]
For Alex’s can:
- Diameter \(=6\), so radius \(=3\)
- Height \(=12\)
\[
V_A=\pi(3)^2(12)=108\pi
\]
For Felicia’s can:
- Diameter \(=12\), so radius \(=6\)
- Height \(=6\)
\[
V_F=\pi(6)^2(6)=216\pi
\]
The ratio of Alex’s volume to Felicia’s volume is
\[
108\pi:216\pi
\]
Divide both parts by \(108\pi\):
\[
1:2
\]
Although Alex’s can is twice as tall, Felicia’s radius is twice as large, and radius is squared in the volume formula.
\[
\boxed{1:2}
\]
ANSWER 9: B
Problem 10:
We seek the smallest number greater than 2 that leaves remainder 2 when divided by 3, 4, 5, and 6.
If the number is \(n\), then \(n-2\) must be divisible by all of
\[
3,\ 4,\ 5,\ 6
\]
The least common multiple is
\[
\operatorname{lcm}(3,4,5,6)=60
\]
So the smallest possible value of \(n-2\) is 60:
\[
n-2=60
\]
\[
n=62
\]
The number 62 lies between 61 and 65.
Indeed:
\[
62\div 3,\ 62\div 4,\ 62\div 5,\ 62\div 6
\]
all leave remainder 2.
\[
\boxed{61\text{ and }65}
\]
ANSWER 10: D |
Alex and Felicia each have cats as pets. Alex buys cat food in cylindrical cans that are 6 cm in diameter and 12 cm high. Felicia buys cat food in cylindrical cans that are 12 cm in diameter and 6 cm high. What is the ratio of the volume of one of Alex's cans to the volume of one of Felicia's cans?
| Model | Pick | ✓/✗ | Reasoning |
|---|---|---|---|
openrouter:meta/muse-spark-1.3 |
B | ✓ | showProblem 1: We are asked for the final price after a discount and then tax. Original price is 80 dollars. 25% off means pay 100% - 25% = 75% of original. Sale price = 0.75 × 80 = 60 dollars. Tempting mistake: subtract 25 dollars to get 55. No, 25% means percent, not dollars. Then 10% tax is added to the sale price, not the original price. Tax = 10% of 60 = 6 dollars. Total = 60 + 6 = 66 dollars. Equivalently 1.10 × 60 = 66. Check: A 45 is far too low. B 52 would be 35% off total. C 54 would be adding tax incorrectly. E 68 would be adding 10% of 80. ANSWER 1: D Problem 2: We need total time = time on coastal road + time on highway. Given time on coastal road = 30 minutes for 10 miles. Let coastal speed = v. Then v = 10 miles / 30 min. Highway speed is three times as fast: 3v. Highway distance is 50 miles. Time = distance / speed, so: Highway time = 50 / (3v). From coastal: 10 / v = 30, so 1/v = 3 min per mile. Thus highway time = 50 / 3 × (1/v) = 50/3 × 3 = 50 minutes. Total = 30 + 50 = 80 minutes. Alternative check: Highway is 5 times distance but 3 times speed, so takes 5/3 as long as coastal: 30 × 5/3 = 50. ANSWER 2: C Problem 3: We are told w,x,y,z are whole numbers, so 0,1,2,... And 2^w · 3^x · 5^y · 7^z = 588. Find 2w + 3x + 5y + 7z. Factor 588 into primes. 588 = 58.8 × 10, but do integer: 588 = 2 × 294 = 2 × 2 × 147 = 4 × 147. 147 = 3 × 49 = 3 × 7 × 7. So 588 = 2^2 × 3^1 × 5^0 × 7^2. By uniqueness of prime factorization, exponents must match: w = 2, x = 1, y = 0, z = 2. Note y=0 is allowed because whole numbers include 0, and 5^0 = 1. Now compute linear expression: 2w + 3x + 5y + 7z = 2×2 + 3×1 + 5×0 + 7×2 = 4 + 3 + 0 + 14 = 21. ANSWER 3: A Problem 4: Order the five finishers by time behind Pedro. Let Pedro's time be P. Nico finished 11 minutes behind Pedro: N = P+11. Olympia finished 3 minutes behind Pedro: O = P+3. Olympia finished 2 minutes ahead of Melina: So Melina is 2 minutes behind Olympia: M = O+2 = P+5. Olympia finished 6 minutes ahead of Luke: So Luke is 6 minutes behind Olympia: L = O+6 = P+9. Order by increasing time: Pedro at P+0 — 1st Olympia at P+3 — 2nd Melina at P+5 — 3rd Luke at P+9 — 4th Nico at P+11 — 5th So fourth is Luke. ANSWER 4: A Problem 5: Total elapsed time from boarding morning bus to arriving home. From 7:30 a.m. to 4:00 p.m. = 8.5 hours = 8×60 + 30 = 510 minutes. Time at school: 6 classes × 50 min = 300 min. Lunch 30 min. Additional 2 hours = 120 min. Total school = 300 + 30 + 120 = 450 min. Bus time (morning + afternoon) = total elapsed - school time = 510 - 450 = 60 minutes. Tempting error: miscount 7:30 to 4:00 as 8 hours. ANSWER 5: B Problem 6: Let g = number of girls. Then number of boys b = g+2. Each boy gets b beans, so boys total = b × b = b^2. Each girl gets g beans, so girls total = g × g = g^2. Beans used = 400 - 6 left = 394. So b^2 + g^2 = 394. Substitute: (g+2)^2 + g^2 = 394 g^2 + 4g + 4 + g^2 = 394 2g^2 + 4g - 390 = 0 Divide 2: g^2 + 2g - 195 = 0. Factor 195 = 13 × 15, differing by 2: (g+15)(g-13)=0. Positive solution g = 13. Then b = 15. Total students = 13+15 = 28. Check: 15^2+13^2 =225+169=394 correct. ANSWER 6: B Problem 7: The car travels 30,000 miles. At any moment exactly 4 tires are on the road carrying it. Total tire-miles delivered = 4 tires × 30,000 miles = 120,000 tire-miles. This wear is shared equally among 5 tires by rotation. Per tire = 120,000 / 5 = 24,000 miles. Tempting wrong: 30,000/5 = 6,000 ignores that 4 tires are used at once. 30,000 would mean no rotation. ANSWER 7: C Problem 8: List two-digit multiples of 7: 14,21,28,35,42,49,56,63,70,77,84,91,98. Compute digit sums: 1+4=5, 2+1=3, 2+8=10, 3+5=8, 4+2=6, 4+9=13, 5+6=11, 6+3=9, 7+0=7, 7+7=14, 8+4=12, 9+1=10, 9+8=17. Only two have sum 10: 28 and 91. Their sum = 28+91 = 119. ANSWER 8: A Problem 9: Volume of cylinder = π r^2 h, where r = diameter/2. Alex: diameter 6, so r=3. height 12. V_A = π × 3^2 × 12 = π × 9 × 12 = 108π. Felicia: diameter 12, so r=6. height 6. V_F = π × 6^2 × 6 = π × 36 × 6 = 216π. Ratio V_A : V_F = 108π : 216π = 108:216 = 1:2. Note volume scales with square of radius, so doubling diameter quadruples base area, outweighing halving height. ANSWER 9: B Problem 10: We need N > 2 with N ≡ 2 mod 3, mod 4, mod 5, mod 6. So N-2 is divisible by each of 3,4,5,6. N-2 must be a common multiple of 3,4,5,6. LCM(3,4,5,6): 4=2^2, 6=2×3, so LCM = 2^2 × 3 × 5 = 60. Positive multiples: 60,120,... N=2 gives N-2=0 which works but is excluded by >2. Next smallest is N-2 = 60, so N = 62. 62 is between 61 and 65. Check: 62 ÷ 3 =20 rem 2, ÷4=15 rem 2, etc. ANSWER 10: D |
openrouter:google/gemini-3.8-flash |
B | ✓ | showProblem 1:
**Restatement and Setup:**
We are given an item with an original price of $\$80$. It is discounted by $25\%$, and then a $10\%$ sales tax is applied to this discounted sale price. We need to find the final total selling price.
**Step-by-step computation:**
1. Calculate the discount:
$$\text{Discount} = 25\% \text{ of } \$80 = 0.25 \times 80 = \$20$$
2. Calculate the sale price:
$$\text{Sale Price} = \$80 - \$20 = \$60$$
*(Alternatively, the sale price is $75\%$ of $\$80$: $0.75 \times 80 = \$60$.)*
3. Calculate the tax on the sale price:
$$\text{Tax} = 10\% \text{ of } \$60 = 0.10 \times 60 = \$6$$
4. Calculate the total price:
$$\text{Total Price} = \$60 + \$6 = \$66$$
**Ruling out wrong choices:**
- Choice A ($\$45$) results from incorrectly subtracting both $25\%$ and $10\%$ from the original price, or similar errors.
- Choice B ($\$52$) and Choice C ($\$54$) are too low.
- Choice E ($\$68$) might occur if the tax were incorrectly computed on the original $\$80$ price ($80 \times 0.10 = \$8$) and added to $\$60$.
ANSWER 1: D
---
Problem 2:
**Restatement and Setup:**
Anh drives on two segments:
- Coastal access road: distance $d_c = 10$ miles, time $t_c = 30$ minutes.
- Highway: distance $d_h = 50$ miles.
He drives three times as fast on the highway as on the coastal access road ($v_h = 3 v_c$). We need to find the total time in minutes for the entire trip.
**Step-by-step computation:**
1. Find the speed on the coastal road:
Anh drives $10$ miles in $30$ minutes ($0.5$ hours).
$$v_c = \frac{10\text{ miles}}{0.5\text{ hours}} = 20\text{ mph}$$
2. Find the speed on the highway:
$$v_h = 3 \times v_c = 3 \times 20\text{ mph} = 60\text{ mph} = 1\text{ mile per minute}$$
3. Find the time spent on the highway:
$$t_h = \frac{50\text{ miles}}{1\text{ mile per minute}} = 50\text{ minutes}$$
4. Find the total trip time:
$$\text{Total time} = t_c + t_h = 30\text{ minutes} + 50\text{ minutes} = 80\text{ minutes}$$
**Ruling out wrong choices:**
- Choice A ($50$) is just the time on the highway.
- Choices B ($70$), D ($90$), and E ($100$) arise from miscalculating the highway speed ratio or mixing up minutes and hours.
ANSWER 2: C
---
Problem 3:
**Restatement and Setup:**
Given whole numbers (non-negative integers) $w, x, y, z$ such that:
$$2^w \cdot 3^x \cdot 5^y \cdot 7^z = 588$$
We need to find the value of $2w + 3x + 5y + 7z$.
**Step-by-step computation:**
1. Find the prime factorization of $588$:
$$588 = 2 \times 294 = 2 \times 2 \times 147 = 4 \times 3 \times 49 = 2^2 \times 3^1 \times 7^2$$
2. Matching the prime factors with $2^w \cdot 3^x \cdot 5^y \cdot 7^z$:
- $w = 2$
- $x = 1$
- $y = 0$ (since $5$ is not a factor of $588$)
- $z = 2$
3. Compute the required expression $2w + 3x + 5y + 7z$:
$$2(2) + 3(1) + 5(0) + 7(2) = 4 + 3 + 0 + 14 = 21$$
**Ruling out wrong choices:**
- If one mistakenly sets $y=1$, the sum would be $21 + 5 = 26$ (close to 25 or 27).
- Choices B, C, D, and E do not match the evaluated sum of $21$.
ANSWER 3: A
---
Problem 4:
**Restatement and Setup:**
Five runners (Luke, Melina, Nico, Olympia, Pedro) finished a race. We are given relative finish times:
- Nico finished $11$ minutes behind Pedro.
- Olympia finished $3$ minutes behind Pedro.
- Olympia finished $2$ minutes ahead of Melina.
- Olympia finished $6$ minutes ahead of Luke.
We need to determine who finished in fourth place.
**Step-by-step computation:**
Let Pedro's finish time be $t=0$ minutes (the earliest/winner).
- Pedro finishes at $0$ minutes.
- Olympia finished $3$ minutes behind Pedro $\implies$ Olympia finishes at $0 + 3 = 3$ minutes.
- Olympia finished $2$ minutes ahead of Melina $\implies$ Melina finishes $2$ minutes after Olympia $\implies 3 + 2 = 5$ minutes.
- Olympia finished $6$ minutes ahead of Luke $\implies$ Luke finishes $6$ minutes after Olympia $\implies 3 + 6 = 9$ minutes.
- Nico finished $11$ minutes behind Pedro $\implies$ Nico finishes at $0 + 11 = 11$ minutes.
Listing the runners in order of finish:
1. Pedro ($0$ min)
2. Olympia ($3$ min)
3. Melina ($5$ min)
4. Luke ($9$ min)
5. Nico ($11$ min)
Thus, Luke finished fourth.
**Ruling out wrong choices:**
- Pedro was 1st, Olympia was 2nd, Melina was 3rd, and Nico was 5th (last).
ANSWER 4: A
---
Problem 5:
**Restatement and Setup:**
Walter boards the bus at 7:30 a.m. and arrives home from the bus at 4:00 p.m.
During the day, he spends time on the bus (both ways) and at school.
School activities consist of:
- $6$ classes of $50$ minutes each
- $30$ minutes for lunch
- $2$ hours of additional time
We need to find the total time Walter spent on the bus.
**Step-by-step computation:**
1. Calculate total elapsed time between leaving home and returning:
- From 7:30 a.m. to 12:00 p.m. is $4$ hours and $30$ minutes ($4.5$ hours).
- From 12:00 p.m. to 4:00 p.m. is $4$ hours.
- Total elapsed time = $8$ hours and $30$ minutes $= 8 \times 60 + 30 = 510$ minutes.
2. Calculate total time spent on school activities:
- Classes: $6 \times 50\text{ minutes} = 300\text{ minutes}$
- Lunch: $30\text{ minutes}$
- Additional time: $2\text{ hours} = 120\text{ minutes}$
- Total school time $= 300 + 30 + 120 = 450\text{ minutes}$.
3. Calculate time spent on the bus:
$$\text{Bus time} = \text{Total time} - \text{School time} = 510 - 450 = 60\text{ minutes}$$
**Ruling out wrong choices:**
- 30 minutes assumes only a one-way trip or forgets additional school time.
- 75, 90, 120 minutes result from miscounting the elapsed time or forgetting the 30-minute lunch.
ANSWER 5: B
---
Problem 6:
**Restatement and Setup:**
Let $b$ be the number of boys and $g$ be the number of girls.
- Each boy receives $b$ jelly beans (total $b^2$).
- Each girl receives $g$ jelly beans (total $g^2$).
- Total jelly beans distributed: $400 - 6 = 394$.
- There are two more boys than girls: $b = g + 2$.
We need to find the total number of students in the class, which is $b + g$.
**Step-by-step com |
openrouter:~z-ai/glm-latest |
B | ✓ | show# Problem 1: **What is asked:** Find the final price after a 25% discount on $80, followed by 10% tax on the *sale price*. **Step 1 — Compute the sale price (25% off):** Discount = 25% of 80 = 0.25 × 80 = $20. Sale price = 80 − 20 = **$60**. **Step 2 — Add 10% tax to the sale price:** Tax = 10% of 60 = $6. Total = 60 + 6 = **$66**. **Rule out wrong answers:** - $52 (B) comes from wrongly taking 10% off the *original* price (60 − 8), but tax is added, not discounted. - $54 (C) comes from adding discounts: 80 × 0.75 × 0.9 — but tax increases the price. - The correct sequence is 80 → 60 → 66. ANSWER 1: D # Problem 2: **What is asked:** Find the total driving time in minutes. **Step 1 — Coastal road speed:** Anh drove 10 miles in 30 minutes (= 0.5 hour). Speed = 10 ÷ 0.5 = **20 mph**. **Step 2 — Highway speed:** He drove 3 times as fast: 3 × 20 = **60 mph**. **Step 3 — Highway time:** Time = distance ÷ speed = 50 ÷ 60 = 5/6 hour = **50 minutes**. **Step 4 — Total time:** 30 + 50 = **80 minutes**. **Rule out wrong answers:** - 90 (D) would result from wrongly assuming equal speeds (30 min + 60 min); but the highway was faster, so its time is *less* than 60 minutes. Only 80 fits. ANSWER 2: C # Problem 3: **What is asked:** Given 2^w · 3^x · 5^y · 7^z = 588, find 2w + 3x + 5y + 7z. **Step 1 — Factor 588:** 588 = 4 × 147 = 4 × 3 × 49 = 2² × 3 × 7². **Step 2 — Read off exponents:** 588 = 2² · 3¹ · 5⁰ · 7², so w = 2, x = 1, y = 0, z = 2. **Step 3 — Compute the expression:** 2w + 3x + 5y + 7z = 2(2) + 3(1) + 5(0) + 7(2) = 4 + 3 + 0 + 14 = **21**. **Rule out wrong answers:** 35 (D) or 56 (E) would come from confusing the coefficients 2,3,5,7 with the bases; note 588 is not divisible by 5, forcing y = 0. ANSWER 3: A # Problem 4: **What is asked:** Determine which runner finished fourth (in order of finishing time). **Step 1 — Set Pedro's time as P (a reference).** Then: - Nico finished 11 minutes behind Pedro: Nico = P + 11. - Olympia finished 3 minutes behind Pedro: Olympia = P + 3. - Olympia finished 2 minutes ahead of Melina, so Melina = P + 3 + 2 = P + 5. - Olympia finished 6 minutes ahead of Luke, so Luke = P + 3 + 6 = P + 9. **Step 2 — Order from fastest to slowest:** Pedro (P), Olympia (P+3), Melina (P+5), Luke (P+9), Nico (P+11). **Step 3 — Fourth place** is **Luke**. **Rule out wrong answers:** Nico (C) is last (5th), Pedro (E) is first; a common error is swapping Luke and Melina — but Luke = P+9 is behind Melina = P+5. ANSWER 4: A # Problem 5: **What is asked:** Total time Walter spent on the bus (both ways). **Step 1 — Total elapsed time from 7:30 a.m. to 4:00 p.m.:** That is 8 hours 30 minutes = 510 minutes. **Step 2 — Time accounted for at school:** - Classes: 6 × 50 = 300 minutes - Lunch: 30 minutes - Additional time: 2 hours = 120 minutes - Total school time: 300 + 30 + 120 = 450 minutes. **Step 3 — Bus time:** 510 − 450 = **60 minutes**. **Rule out wrong answers:** 90 (D) would ignore lunch or additional time; 30 (A) would count only one bus ride — but the round trip must be 60 minutes total. ANSWER 5: B # Problem 6: **What is asked:** Find the total number of students. **Step 1 — Set up equations.** Let g = number of girls, b = number of boys. Each boy gets b beans (b boys), each girl gets g beans (g girls): b² + g² = 400 − 6 = 394, and b = g + 2. **Step 2 — Substitute and solve:** (g+2)² + g² = 394 g² + 4g + 4 + g² = 394 2g² + 4g − 390 = 0 g² + 2g − 195 = 0 (g + 15)(g − 13) = 0 → g = 13 (reject −15). **Step 3 — Find the total:** Boys: b = 13 + 2 = 15. Total students = 15 + 13 = **28**. **Check:** 15² + 13² = 225 + 169 = 394 = 400 − 6. ✓ ANSWER 6: B # Problem 7: **What is asked:** Miles each of the 5 tires was used over 30,000 miles. **Step 1 — Total tire-miles used:** At any moment the car uses 4 tires. Over 30,000 miles, total tire-miles = 4 × 30,000 = 120,000. **Step 2 — Split equally among 5 tires:** 120,000 ÷ 5 = **24,000 miles** each. **Rule out wrong answers:** 30,000 (D) is wrong because no single tire can be used the whole time when 5 tires share the work; 6,000 (A) and 7,500 (B) wrongly divide by the wrong quantity (e.g., 30,000 ÷ 5 or ÷ 4). ANSWER 7: C # Problem 8: **What is asked:** Sum of the two two-digit multiples of 7 whose digits sum to 10. **Step 1 — List two-digit multiples of 7 and digit sums:** 14 (5), 21 (3), **28 (10)** ✓, 35 (8), 42 (6), 49 (13), 56 (11), 63 (9), 70 (7), 77 (14), 84 (12), **91 (10)** ✓, 98 (17). **Step 2 — Identify the two qualifying numbers:** 28 and 91. **Step 3 — Sum:** 28 + 91 = **119**. **Rule out wrong answers:** 126 (B) is 63 + 63 — impossible since numbers are distinct; 140 (D) might come from 28 + 112 (but 112 is three digits). ANSWER 8: A # Problem 9: **What is asked:** Ratio of Alex's can volume to Felicia's can volume. **Step 1 — Volume formula:** V = πr²h. **Step 2 — Alex's can:** diameter 6 → radius 3; height 12. V_A = π(3)²(12) = 108π. **Step 3 — Felicia's can:** diameter 12 → radius 6; height 6. V_F = π(6)²(6) = 216π. **Step 4 — Ratio:** V_A : V_F = 108π : 216π = **1 : 2**. **Rule out wrong answers:** 1:1 (C) is the tempting "swapped dimensions" intuition, but volume depends on the *square* of the radius, so doubling the radius quadruples that factor while halving the height only halves — net effect is Felicia's can is twice as big. ANSWER 9: B # Problem 10: **What is asked:** Find the smallest number > 2 that leaves remainder 2 when divided by 3, 4, 5, and 6, and identify the interval containing it. **Step 1 — Interpret the condition:** N − 2 must be divisible by 3, 4, 5, and 6, i.e., N − 2 is a multiple of LCM(3, 4, 5, 6). **Step 2 — Compute the LCM:** LCM(3,4,5,6) = 60 (since 60 is divisible by 3, 4, 5, and 6). **Step 3 — Candidates:** N = 60k + 2 for whole numbers k: N = 2, 62, 122, ... The smallest *greater than 2* is **62**. **Step 4 — Locate 62:** It lies between **61 and 65**. **Rule out wrong answers:** 42 + 2 = 44 is a common error (using 42, the LCM of only |
openrouter:qwen/qwen3.8-27b |
B | ✓ | showProblem 1:
The dress is originally priced at \$80. A 25% discount means the sale price is
\[
80(1-0.25)=80(0.75)=60.
\]
Then 10% tax is added to the sale price:
\[
60(1+0.10)=60(1.10)=66.
\]
So the total selling price is \$66.
ANSWER 1: D
Problem 2:
Anh drove 10 miles on the coastal road in 30 minutes, so his coastal-road speed was
\[
\frac{10\text{ miles}}{30\text{ minutes}}.
\]
He drove three times as fast on the highway. Therefore, for the same distance, the highway time would be one-third as long.
For 50 miles on the highway, if he had driven at coastal-road speed, it would take
\[
30 \times \frac{50}{10}=150
\]
minutes. But because he drove three times as fast on the highway, the actual highway time is
\[
\frac{150}{3}=50
\]
minutes.
The coastal road took 30 minutes, so the total trip time was
\[
30+50=80
\]
minutes.
ANSWER 2: C
Problem 3:
The equation should be read as
\[
2^w \cdot 3^x \cdot 5^y \cdot 7^z = 588.
\]
Factor 588:
\[
588=2\cdot 294=2^2\cdot 147=2^2\cdot 3\cdot 49=2^2\cdot 3^1\cdot 7^2.
\]
There is no factor of 5, so \(y=0\). Comparing prime exponents gives
\[
w=2,\qquad x=1,\qquad y=0,\qquad z=2.
\]
Now compute
\[
2w+3x+5y+7z=2(2)+3(1)+5(0)+7(2).
\]
\[
=4+3+0+14=21.
\]
ANSWER 3: A
Problem 4:
Let Pedro’s finishing time be \(P\). In a race, a smaller time means finishing earlier.
- Nico finished 11 minutes behind Pedro, so Nico’s time is
\[
P+11.
\]
- Olympia finished 3 minutes behind Pedro, so Olympia’s time is
\[
P+3.
\]
- Olympia finished 2 minutes ahead of Melina, so Melina’s time is
\[
(P+3)+2=P+5.
\]
- Olympia finished 6 minutes ahead of Luke, so Luke’s time is
\[
(P+3)+6=P+9.
\]
Now order the runners from first to last by increasing time:
\[
P,\quad P+3,\quad P+5,\quad P+9,\quad P+11.
\]
That is:
1. Pedro
2. Olympia
3. Melina
4. Luke
5. Nico
So the fourth runner was Luke.
ANSWER 4: A
Problem 5:
From 7:30 a.m. to 4:00 p.m. is 8 hours and 30 minutes:
\[
8(60)+30=480+30=510
\]
minutes.
Walter’s time in school not spent on the bus is:
- 6 classes of 50 minutes each:
\[
6(50)=300
\]
minutes;
- lunch: 30 minutes;
- additional time: 2 hours = 120 minutes.
Total non-bus time:
\[
300+30+120=450
\]
minutes.
So his total bus time was
\[
510-450=60
\]
minutes.
ANSWER 5: B
Problem 6:
Let the number of girls be \(g\). Since there were two more boys than girls, the number of boys is
\[
g+2.
\]
Mrs. Awesome gave each boy as many jelly beans as there were boys, so the boys received
\[
(g+2)^2
\]
jelly beans total. Each girl received as many as there were girls, so the girls received
\[
g^2
\]
jelly beans total.
She had 400 jelly beans and 6 left, so she gave away
\[
400-6=394.
\]
Thus,
\[
(g+2)^2+g^2=394.
\]
Expand:
\[
g^2+4g+4+g^2=394
\]
\[
2g^2+4g+4=394
\]
\[
2g^2+4g-390=0
\]
Divide by 2:
\[
g^2+2g-195=0.
\]
Factor:
\[
(g+15)(g-13)=0.
\]
Since \(g\) must be positive,
\[
g=13.
\]
Then the number of boys is
\[
13+2=15.
\]
The total number of students is
\[
13+15=28.
\]
ANSWER 6: B
Problem 7:
During the first 30,000 miles, the car was always using 4 tires at once. Therefore, the total “tire-miles” used is
\[
4 \times 30{,}000=120{,}000.
\]
There are 5 tires total, and they were all used the same number of miles. So each tire was used for
\[
\frac{120{,}000}{5}=24{,}000
\]
miles.
ANSWER 7: C
Problem 8:
We need two-digit multiples of 7 whose digits sum to 10.
The two-digit multiples of 7 are:
\[
14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84, 91, 98.
\]
Check digit sums:
\[
14: 1+4=5
\]
\[
21: 2+1=3
\]
\[
28: 2+8=10
\]
\[
35: 3+5=8
\]
\[
42: 4+2=6
\]
\[
49: 4+9=13
\]
\[
56: 5+6=11
\]
\[
63: 6+3=9
\]
\[
70: 7+0=7
\]
\[
77: 7+7=14
\]
\[
84: 8+4=12
\]
\[
91: 9+1=10
\]
\[
98: 9+8=17
\]
The only two are 28 and 91. Their sum is
\[
28+91=119.
\]
ANSWER 8: A
Problem 9:
The volume of a cylinder is
\[
V=\pi r^2h.
\]
Alex’s cans have diameter 6 cm, so radius 3 cm, and height 12 cm:
\[
V_A=\pi(3^2)(12)=\pi(9)(12)=108\pi.
\]
Felicia’s cans have diameter 12 cm, so radius 6 cm, and height 6 cm:
\[
V_F=\pi(6^2)(6)=\pi(36)(6)=216\pi.
\]
The ratio of Alex’s can volume to Felicia’s can volume is
\[
108\pi:216\pi=108:216=1:2.
\]
ANSWER 9: B
Problem 10:
Let the number be \(N\). It leaves a remainder of 2 when divided by 3, 4, 5, and 6, so
\[
N-2
\]
is divisible by 3, 4, 5, and 6. Therefore, \(N-2\) must be a multiple of the least common multiple of 3, 4, 5, and 6.
Find the LCM:
\[
\operatorname{lcm}(3,4,5,6)=60.
\]
So
\[
N-2=60k
\]
for some positive integer \(k\), because we need \(N>2\).
The smallest possible value is when \(k=1\):
\[
N-2=60
\]
\[
N=62.
\]
This lies between 61 and 65.
ANSWER 10: D |
openrouter:anthropic/claude-opus-5 |
B | ✓ | showProblem 1: Sale price: 25% off means you pay 75%: 80 × 0.75 = 60 dollars. Add 10% tax: 60 × 1.10 = 66 dollars. (Choice C, 54, would come from subtracting 10%; choice D is correct. Note taking 25% off then adding 10% doesn't return to 80.) ANSWER 1: D Problem 2: Coastal road: 10 miles in 30 minutes, so 3 minutes per mile. Highway speed is 3 times as fast, so 1 minute per mile. Highway time: 50 miles × 1 minute/mile = 50 minutes. Total: 50 + 30 = 80 minutes. (Choice A forgets the coastal 30 minutes; choice D would come from using 3 min/mile on the highway incorrectly.) ANSWER 2: C Problem 3: The equation is 2^w · 3^x · 5^y · 7^z = 588. Factor 588 = 4 · 147 = 2² · 3 · 7². So w = 2, x = 1, y = 0, z = 2. Then 2w + 3x + 5y + 7z = 2(2) + 3(1) + 5(0) + 7(2) = 4 + 3 + 0 + 14 = 21. ANSWER 3: A Problem 4: Let Pedro's time be 0 (he's a reference). - Nico = +11 - Olympia = +3 (3 min behind Pedro) - Melina = Olympia + 2 = +5 - Luke = Olympia + 6 = +9 Order from first: Pedro (0), Olympia (3), Melina (5), Luke (9), Nico (11). Fourth place is Luke. ANSWER 4: A Problem 5: Total time away: 7:30 a.m. to 4:00 p.m. = 8 hours 30 minutes = 510 minutes. Time at school: classes 6 × 50 = 300, lunch 30, extra 2 hours = 120; total 450 minutes. Bus time = 510 − 450 = 60 minutes (both trips combined). ANSWER 5: B Problem 6: Let g = number of girls, b = g + 2 boys. Jelly beans used: b² + g² = 400 − 6 = 394. (g + 2)² + g² = 394 → 2g² + 4g + 4 = 394 → g² + 2g − 195 = 0 → (g + 15)(g − 13) = 0 → g = 13. So girls = 13, boys = 15; check 169 + 225 = 394 ✓. Total students = 28. ANSWER 6: B Problem 7: Four tires are on the road at any time, so total tire-miles = 4 × 30,000 = 120,000. Shared equally among 5 tires: 120,000 ÷ 5 = 24,000 miles each. (30,000 would be if no rotation; 6,000 is the rest time per tire, not use.) ANSWER 7: C Problem 8: Two-digit multiples of 7: 14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84, 91, 98. Digit sums: 5, 3, 10, 8, 6, 13, 11, 9, 7, 14, 12, 10, 17. Digit sum 10 occurs for 28 and 91. Sum: 28 + 91 = 119. ANSWER 8: A Problem 9: Alex: diameter 6 → radius 3, height 12: V = π(3²)(12) = 108π. Felicia: diameter 12 → radius 6, height 6: V = π(6²)(6) = 216π. Ratio = 108π : 216π = 1 : 2. (Doubling the radius quadruples volume, while halving height only halves it, so Felicia's is twice as big — not equal.) ANSWER 9: B Problem 10: A number leaving remainder 2 when divided by 3, 4, 5, and 6 must be 2 more than a common multiple of 3, 4, 5, 6. LCM(3, 4, 5, 6) = 60, so the smallest such number greater than 2 is 60 + 2 = 62. 62 lies between 61 and 65. ANSWER 10: D |
openrouter:openai/gpt-5.6-terra-pro |
B | ✓ | showProblem 1:
The dress was originally priced at \$80.
A 25% discount means the sale price is \(75\%\) of the original price:
\[
80 \times 0.75=60
\]
Then 10% tax is added:
\[
10\% \text{ of } 60 = 6
\]
So the total price is
\[
60+6=66
\]
A common mistake is to subtract 25% and add 10% of the original \$80, but the tax is added to the reduced sale price, not the original price.
\[
\boxed{66}
\]
ANSWER 1: D
Problem 2:
Anh drove 10 miles on the coastal road in 30 minutes.
Since 30 minutes is \(\frac12\) hour, his coastal-road speed was
\[
\frac{10\text{ miles}}{\frac12\text{ hour}}=20\text{ miles per hour}
\]
He drove three times as fast on the highway:
\[
3(20)=60\text{ miles per hour}
\]
The highway trip was 50 miles, so the highway driving time was
\[
\frac{50}{60}\text{ hour}=\frac56\text{ hour}
\]
Convert \(\frac56\) hour to minutes:
\[
\frac56\cdot 60=50\text{ minutes}
\]
His total driving time was
\[
30+50=80\text{ minutes}
\]
The answer is not 50 minutes, since that is only the highway time.
\[
\boxed{80}
\]
ANSWER 2: C
Problem 3:
We are told that
\[
2^w\cdot 3^x\cdot 5^y\cdot 7^z=588
\]
Factor 588 into primes:
\[
588=2\cdot 294=2^2\cdot 147=2^2\cdot 3\cdot 49
\]
Thus,
\[
588=2^2\cdot 3^1\cdot 5^0\cdot 7^2
\]
So
\[
w=2,\qquad x=1,\qquad y=0,\qquad z=2
\]
Now calculate:
\[
2w+3x+5y+7z
\]
\[
=2(2)+3(1)+5(0)+7(2)
\]
\[
=4+3+0+14=21
\]
The factor \(5^0\) is important: since 588 has no factor of 5, \(y=0\), not 1.
\[
\boxed{21}
\]
ANSWER 3: A
Problem 4:
We compare all runners’ finishing times relative to Pedro.
- Nico finished 11 minutes behind Pedro.
- Olympia finished 3 minutes behind Pedro.
- Olympia finished 2 minutes ahead of Melina, so Melina finished 2 minutes behind Olympia.
- Olympia finished 6 minutes ahead of Luke, so Luke finished 6 minutes behind Olympia.
Let Pedro finish at time 0.
Then:
\[
\begin{array}{c|c}
\text{Runner} & \text{Minutes behind Pedro} \\
\hline
\text{Pedro} & 0\\
\text{Olympia} & 3\\
\text{Melina} & 3+2=5\\
\text{Luke} & 3+6=9\\
\text{Nico} & 11
\end{array}
\]
Therefore, the order is:
1. Pedro
2. Olympia
3. Melina
4. Luke
5. Nico
So Luke finished fourth.
\[
\boxed{\text{Luke}}
\]
ANSWER 4: A
Problem 5:
Walter is at school from 7:30 a.m. until 4:00 p.m.
That is:
\[
8\text{ hours }30\text{ minutes}=510\text{ minutes}
\]
His school-day activities take:
- 6 classes of 50 minutes each:
\[
6\cdot 50=300\text{ minutes}
\]
- Lunch:
\[
30\text{ minutes}
\]
- Additional school time:
\[
2\text{ hours}=120\text{ minutes}
\]
Total time not spent on the bus:
\[
300+30+120=450\text{ minutes}
\]
Therefore, bus time is
\[
510-450=60\text{ minutes}
\]
This includes both the ride to school and the ride home.
\[
\boxed{60}
\]
ANSWER 5: B
Problem 6:
Let the number of girls be \(g\).
There are two more boys than girls, so the number of boys is
\[
g+2
\]
Each boy receives as many jelly beans as there are boys, so the boys receive
\[
(g+2)(g+2)=(g+2)^2
\]
jelly beans altogether.
Each girl receives \(g\) jelly beans, so the girls receive
\[
g^2
\]
jelly beans altogether.
Mrs. Awesome gave away
\[
400-6=394
\]
jelly beans. Therefore,
\[
g^2+(g+2)^2=394
\]
Expand:
\[
g^2+g^2+4g+4=394
\]
\[
2g^2+4g-390=0
\]
Divide by 2:
\[
g^2+2g-195=0
\]
Factor:
\[
(g+15)(g-13)=0
\]
So
\[
g=13
\]
since a number of girls cannot be negative.
Thus boys:
\[
13+2=15
\]
Total students:
\[
13+15=28
\]
\[
\boxed{28}
\]
ANSWER 6: B
Problem 7:
During the first 30,000 miles, the car always uses 4 tires on the road.
So the total number of tire-miles used is
\[
4\cdot 30{,}000=120{,}000
\]
There are 5 tires total, and they were rotated so each tire was used equally.
Therefore, each tire was used
\[
\frac{120{,}000}{5}=24{,}000
\]
miles.
It is not 30,000 miles because only four of the five tires are being driven on at any one time.
\[
\boxed{24{,}000}
\]
ANSWER 7: C
Problem 8:
We need two-digit multiples of 7 whose digits add to 10.
The two-digit multiples of 7 are:
\[
14,21,28,35,42,49,56,63,70,77,84,91,98
\]
Check digit sums:
\[
28:\quad 2+8=10
\]
\[
91:\quad 9+1=10
\]
These are the only two.
Their sum is
\[
28+91=119
\]
\[
\boxed{119}
\]
ANSWER 8: A
Problem 9:
The volume of a cylinder is
\[
V=\pi r^2h
\]
For Alex’s can:
- Diameter \(=6\), so radius \(=3\)
- Height \(=12\)
\[
V_A=\pi(3)^2(12)=108\pi
\]
For Felicia’s can:
- Diameter \(=12\), so radius \(=6\)
- Height \(=6\)
\[
V_F=\pi(6)^2(6)=216\pi
\]
The ratio of Alex’s volume to Felicia’s volume is
\[
108\pi:216\pi
\]
Divide both parts by \(108\pi\):
\[
1:2
\]
Although Alex’s can is twice as tall, Felicia’s radius is twice as large, and radius is squared in the volume formula.
\[
\boxed{1:2}
\]
ANSWER 9: B
Problem 10:
We seek the smallest number greater than 2 that leaves remainder 2 when divided by 3, 4, 5, and 6.
If the number is \(n\), then \(n-2\) must be divisible by all of
\[
3,\ 4,\ 5,\ 6
\]
The least common multiple is
\[
\operatorname{lcm}(3,4,5,6)=60
\]
So the smallest possible value of \(n-2\) is 60:
\[
n-2=60
\]
\[
n=62
\]
The number 62 lies between 61 and 65.
Indeed:
\[
62\div 3,\ 62\div 4,\ 62\div 5,\ 62\div 6
\]
all leave remainder 2.
\[
\boxed{61\text{ and }65}
\]
ANSWER 10: D |
The smallest number greater than 2 that leaves a remainder of 2 when divided by 3, 4, 5, or 6 lies between what numbers?
| Model | Pick | ✓/✗ | Reasoning |
|---|---|---|---|
openrouter:meta/muse-spark-1.3 |
D | ✓ | showProblem 1: We are asked for the final price after a discount and then tax. Original price is 80 dollars. 25% off means pay 100% - 25% = 75% of original. Sale price = 0.75 × 80 = 60 dollars. Tempting mistake: subtract 25 dollars to get 55. No, 25% means percent, not dollars. Then 10% tax is added to the sale price, not the original price. Tax = 10% of 60 = 6 dollars. Total = 60 + 6 = 66 dollars. Equivalently 1.10 × 60 = 66. Check: A 45 is far too low. B 52 would be 35% off total. C 54 would be adding tax incorrectly. E 68 would be adding 10% of 80. ANSWER 1: D Problem 2: We need total time = time on coastal road + time on highway. Given time on coastal road = 30 minutes for 10 miles. Let coastal speed = v. Then v = 10 miles / 30 min. Highway speed is three times as fast: 3v. Highway distance is 50 miles. Time = distance / speed, so: Highway time = 50 / (3v). From coastal: 10 / v = 30, so 1/v = 3 min per mile. Thus highway time = 50 / 3 × (1/v) = 50/3 × 3 = 50 minutes. Total = 30 + 50 = 80 minutes. Alternative check: Highway is 5 times distance but 3 times speed, so takes 5/3 as long as coastal: 30 × 5/3 = 50. ANSWER 2: C Problem 3: We are told w,x,y,z are whole numbers, so 0,1,2,... And 2^w · 3^x · 5^y · 7^z = 588. Find 2w + 3x + 5y + 7z. Factor 588 into primes. 588 = 58.8 × 10, but do integer: 588 = 2 × 294 = 2 × 2 × 147 = 4 × 147. 147 = 3 × 49 = 3 × 7 × 7. So 588 = 2^2 × 3^1 × 5^0 × 7^2. By uniqueness of prime factorization, exponents must match: w = 2, x = 1, y = 0, z = 2. Note y=0 is allowed because whole numbers include 0, and 5^0 = 1. Now compute linear expression: 2w + 3x + 5y + 7z = 2×2 + 3×1 + 5×0 + 7×2 = 4 + 3 + 0 + 14 = 21. ANSWER 3: A Problem 4: Order the five finishers by time behind Pedro. Let Pedro's time be P. Nico finished 11 minutes behind Pedro: N = P+11. Olympia finished 3 minutes behind Pedro: O = P+3. Olympia finished 2 minutes ahead of Melina: So Melina is 2 minutes behind Olympia: M = O+2 = P+5. Olympia finished 6 minutes ahead of Luke: So Luke is 6 minutes behind Olympia: L = O+6 = P+9. Order by increasing time: Pedro at P+0 — 1st Olympia at P+3 — 2nd Melina at P+5 — 3rd Luke at P+9 — 4th Nico at P+11 — 5th So fourth is Luke. ANSWER 4: A Problem 5: Total elapsed time from boarding morning bus to arriving home. From 7:30 a.m. to 4:00 p.m. = 8.5 hours = 8×60 + 30 = 510 minutes. Time at school: 6 classes × 50 min = 300 min. Lunch 30 min. Additional 2 hours = 120 min. Total school = 300 + 30 + 120 = 450 min. Bus time (morning + afternoon) = total elapsed - school time = 510 - 450 = 60 minutes. Tempting error: miscount 7:30 to 4:00 as 8 hours. ANSWER 5: B Problem 6: Let g = number of girls. Then number of boys b = g+2. Each boy gets b beans, so boys total = b × b = b^2. Each girl gets g beans, so girls total = g × g = g^2. Beans used = 400 - 6 left = 394. So b^2 + g^2 = 394. Substitute: (g+2)^2 + g^2 = 394 g^2 + 4g + 4 + g^2 = 394 2g^2 + 4g - 390 = 0 Divide 2: g^2 + 2g - 195 = 0. Factor 195 = 13 × 15, differing by 2: (g+15)(g-13)=0. Positive solution g = 13. Then b = 15. Total students = 13+15 = 28. Check: 15^2+13^2 =225+169=394 correct. ANSWER 6: B Problem 7: The car travels 30,000 miles. At any moment exactly 4 tires are on the road carrying it. Total tire-miles delivered = 4 tires × 30,000 miles = 120,000 tire-miles. This wear is shared equally among 5 tires by rotation. Per tire = 120,000 / 5 = 24,000 miles. Tempting wrong: 30,000/5 = 6,000 ignores that 4 tires are used at once. 30,000 would mean no rotation. ANSWER 7: C Problem 8: List two-digit multiples of 7: 14,21,28,35,42,49,56,63,70,77,84,91,98. Compute digit sums: 1+4=5, 2+1=3, 2+8=10, 3+5=8, 4+2=6, 4+9=13, 5+6=11, 6+3=9, 7+0=7, 7+7=14, 8+4=12, 9+1=10, 9+8=17. Only two have sum 10: 28 and 91. Their sum = 28+91 = 119. ANSWER 8: A Problem 9: Volume of cylinder = π r^2 h, where r = diameter/2. Alex: diameter 6, so r=3. height 12. V_A = π × 3^2 × 12 = π × 9 × 12 = 108π. Felicia: diameter 12, so r=6. height 6. V_F = π × 6^2 × 6 = π × 36 × 6 = 216π. Ratio V_A : V_F = 108π : 216π = 108:216 = 1:2. Note volume scales with square of radius, so doubling diameter quadruples base area, outweighing halving height. ANSWER 9: B Problem 10: We need N > 2 with N ≡ 2 mod 3, mod 4, mod 5, mod 6. So N-2 is divisible by each of 3,4,5,6. N-2 must be a common multiple of 3,4,5,6. LCM(3,4,5,6): 4=2^2, 6=2×3, so LCM = 2^2 × 3 × 5 = 60. Positive multiples: 60,120,... N=2 gives N-2=0 which works but is excluded by >2. Next smallest is N-2 = 60, so N = 62. 62 is between 61 and 65. Check: 62 ÷ 3 =20 rem 2, ÷4=15 rem 2, etc. ANSWER 10: D |
openrouter:google/gemini-3.8-flash |
D | ✓ | showProblem 1:
**Restatement and Setup:**
We are given an item with an original price of $\$80$. It is discounted by $25\%$, and then a $10\%$ sales tax is applied to this discounted sale price. We need to find the final total selling price.
**Step-by-step computation:**
1. Calculate the discount:
$$\text{Discount} = 25\% \text{ of } \$80 = 0.25 \times 80 = \$20$$
2. Calculate the sale price:
$$\text{Sale Price} = \$80 - \$20 = \$60$$
*(Alternatively, the sale price is $75\%$ of $\$80$: $0.75 \times 80 = \$60$.)*
3. Calculate the tax on the sale price:
$$\text{Tax} = 10\% \text{ of } \$60 = 0.10 \times 60 = \$6$$
4. Calculate the total price:
$$\text{Total Price} = \$60 + \$6 = \$66$$
**Ruling out wrong choices:**
- Choice A ($\$45$) results from incorrectly subtracting both $25\%$ and $10\%$ from the original price, or similar errors.
- Choice B ($\$52$) and Choice C ($\$54$) are too low.
- Choice E ($\$68$) might occur if the tax were incorrectly computed on the original $\$80$ price ($80 \times 0.10 = \$8$) and added to $\$60$.
ANSWER 1: D
---
Problem 2:
**Restatement and Setup:**
Anh drives on two segments:
- Coastal access road: distance $d_c = 10$ miles, time $t_c = 30$ minutes.
- Highway: distance $d_h = 50$ miles.
He drives three times as fast on the highway as on the coastal access road ($v_h = 3 v_c$). We need to find the total time in minutes for the entire trip.
**Step-by-step computation:**
1. Find the speed on the coastal road:
Anh drives $10$ miles in $30$ minutes ($0.5$ hours).
$$v_c = \frac{10\text{ miles}}{0.5\text{ hours}} = 20\text{ mph}$$
2. Find the speed on the highway:
$$v_h = 3 \times v_c = 3 \times 20\text{ mph} = 60\text{ mph} = 1\text{ mile per minute}$$
3. Find the time spent on the highway:
$$t_h = \frac{50\text{ miles}}{1\text{ mile per minute}} = 50\text{ minutes}$$
4. Find the total trip time:
$$\text{Total time} = t_c + t_h = 30\text{ minutes} + 50\text{ minutes} = 80\text{ minutes}$$
**Ruling out wrong choices:**
- Choice A ($50$) is just the time on the highway.
- Choices B ($70$), D ($90$), and E ($100$) arise from miscalculating the highway speed ratio or mixing up minutes and hours.
ANSWER 2: C
---
Problem 3:
**Restatement and Setup:**
Given whole numbers (non-negative integers) $w, x, y, z$ such that:
$$2^w \cdot 3^x \cdot 5^y \cdot 7^z = 588$$
We need to find the value of $2w + 3x + 5y + 7z$.
**Step-by-step computation:**
1. Find the prime factorization of $588$:
$$588 = 2 \times 294 = 2 \times 2 \times 147 = 4 \times 3 \times 49 = 2^2 \times 3^1 \times 7^2$$
2. Matching the prime factors with $2^w \cdot 3^x \cdot 5^y \cdot 7^z$:
- $w = 2$
- $x = 1$
- $y = 0$ (since $5$ is not a factor of $588$)
- $z = 2$
3. Compute the required expression $2w + 3x + 5y + 7z$:
$$2(2) + 3(1) + 5(0) + 7(2) = 4 + 3 + 0 + 14 = 21$$
**Ruling out wrong choices:**
- If one mistakenly sets $y=1$, the sum would be $21 + 5 = 26$ (close to 25 or 27).
- Choices B, C, D, and E do not match the evaluated sum of $21$.
ANSWER 3: A
---
Problem 4:
**Restatement and Setup:**
Five runners (Luke, Melina, Nico, Olympia, Pedro) finished a race. We are given relative finish times:
- Nico finished $11$ minutes behind Pedro.
- Olympia finished $3$ minutes behind Pedro.
- Olympia finished $2$ minutes ahead of Melina.
- Olympia finished $6$ minutes ahead of Luke.
We need to determine who finished in fourth place.
**Step-by-step computation:**
Let Pedro's finish time be $t=0$ minutes (the earliest/winner).
- Pedro finishes at $0$ minutes.
- Olympia finished $3$ minutes behind Pedro $\implies$ Olympia finishes at $0 + 3 = 3$ minutes.
- Olympia finished $2$ minutes ahead of Melina $\implies$ Melina finishes $2$ minutes after Olympia $\implies 3 + 2 = 5$ minutes.
- Olympia finished $6$ minutes ahead of Luke $\implies$ Luke finishes $6$ minutes after Olympia $\implies 3 + 6 = 9$ minutes.
- Nico finished $11$ minutes behind Pedro $\implies$ Nico finishes at $0 + 11 = 11$ minutes.
Listing the runners in order of finish:
1. Pedro ($0$ min)
2. Olympia ($3$ min)
3. Melina ($5$ min)
4. Luke ($9$ min)
5. Nico ($11$ min)
Thus, Luke finished fourth.
**Ruling out wrong choices:**
- Pedro was 1st, Olympia was 2nd, Melina was 3rd, and Nico was 5th (last).
ANSWER 4: A
---
Problem 5:
**Restatement and Setup:**
Walter boards the bus at 7:30 a.m. and arrives home from the bus at 4:00 p.m.
During the day, he spends time on the bus (both ways) and at school.
School activities consist of:
- $6$ classes of $50$ minutes each
- $30$ minutes for lunch
- $2$ hours of additional time
We need to find the total time Walter spent on the bus.
**Step-by-step computation:**
1. Calculate total elapsed time between leaving home and returning:
- From 7:30 a.m. to 12:00 p.m. is $4$ hours and $30$ minutes ($4.5$ hours).
- From 12:00 p.m. to 4:00 p.m. is $4$ hours.
- Total elapsed time = $8$ hours and $30$ minutes $= 8 \times 60 + 30 = 510$ minutes.
2. Calculate total time spent on school activities:
- Classes: $6 \times 50\text{ minutes} = 300\text{ minutes}$
- Lunch: $30\text{ minutes}$
- Additional time: $2\text{ hours} = 120\text{ minutes}$
- Total school time $= 300 + 30 + 120 = 450\text{ minutes}$.
3. Calculate time spent on the bus:
$$\text{Bus time} = \text{Total time} - \text{School time} = 510 - 450 = 60\text{ minutes}$$
**Ruling out wrong choices:**
- 30 minutes assumes only a one-way trip or forgets additional school time.
- 75, 90, 120 minutes result from miscounting the elapsed time or forgetting the 30-minute lunch.
ANSWER 5: B
---
Problem 6:
**Restatement and Setup:**
Let $b$ be the number of boys and $g$ be the number of girls.
- Each boy receives $b$ jelly beans (total $b^2$).
- Each girl receives $g$ jelly beans (total $g^2$).
- Total jelly beans distributed: $400 - 6 = 394$.
- There are two more boys than girls: $b = g + 2$.
We need to find the total number of students in the class, which is $b + g$.
**Step-by-step com |
openrouter:~z-ai/glm-latest |
D | ✓ | show# Problem 1: **What is asked:** Find the final price after a 25% discount on $80, followed by 10% tax on the *sale price*. **Step 1 — Compute the sale price (25% off):** Discount = 25% of 80 = 0.25 × 80 = $20. Sale price = 80 − 20 = **$60**. **Step 2 — Add 10% tax to the sale price:** Tax = 10% of 60 = $6. Total = 60 + 6 = **$66**. **Rule out wrong answers:** - $52 (B) comes from wrongly taking 10% off the *original* price (60 − 8), but tax is added, not discounted. - $54 (C) comes from adding discounts: 80 × 0.75 × 0.9 — but tax increases the price. - The correct sequence is 80 → 60 → 66. ANSWER 1: D # Problem 2: **What is asked:** Find the total driving time in minutes. **Step 1 — Coastal road speed:** Anh drove 10 miles in 30 minutes (= 0.5 hour). Speed = 10 ÷ 0.5 = **20 mph**. **Step 2 — Highway speed:** He drove 3 times as fast: 3 × 20 = **60 mph**. **Step 3 — Highway time:** Time = distance ÷ speed = 50 ÷ 60 = 5/6 hour = **50 minutes**. **Step 4 — Total time:** 30 + 50 = **80 minutes**. **Rule out wrong answers:** - 90 (D) would result from wrongly assuming equal speeds (30 min + 60 min); but the highway was faster, so its time is *less* than 60 minutes. Only 80 fits. ANSWER 2: C # Problem 3: **What is asked:** Given 2^w · 3^x · 5^y · 7^z = 588, find 2w + 3x + 5y + 7z. **Step 1 — Factor 588:** 588 = 4 × 147 = 4 × 3 × 49 = 2² × 3 × 7². **Step 2 — Read off exponents:** 588 = 2² · 3¹ · 5⁰ · 7², so w = 2, x = 1, y = 0, z = 2. **Step 3 — Compute the expression:** 2w + 3x + 5y + 7z = 2(2) + 3(1) + 5(0) + 7(2) = 4 + 3 + 0 + 14 = **21**. **Rule out wrong answers:** 35 (D) or 56 (E) would come from confusing the coefficients 2,3,5,7 with the bases; note 588 is not divisible by 5, forcing y = 0. ANSWER 3: A # Problem 4: **What is asked:** Determine which runner finished fourth (in order of finishing time). **Step 1 — Set Pedro's time as P (a reference).** Then: - Nico finished 11 minutes behind Pedro: Nico = P + 11. - Olympia finished 3 minutes behind Pedro: Olympia = P + 3. - Olympia finished 2 minutes ahead of Melina, so Melina = P + 3 + 2 = P + 5. - Olympia finished 6 minutes ahead of Luke, so Luke = P + 3 + 6 = P + 9. **Step 2 — Order from fastest to slowest:** Pedro (P), Olympia (P+3), Melina (P+5), Luke (P+9), Nico (P+11). **Step 3 — Fourth place** is **Luke**. **Rule out wrong answers:** Nico (C) is last (5th), Pedro (E) is first; a common error is swapping Luke and Melina — but Luke = P+9 is behind Melina = P+5. ANSWER 4: A # Problem 5: **What is asked:** Total time Walter spent on the bus (both ways). **Step 1 — Total elapsed time from 7:30 a.m. to 4:00 p.m.:** That is 8 hours 30 minutes = 510 minutes. **Step 2 — Time accounted for at school:** - Classes: 6 × 50 = 300 minutes - Lunch: 30 minutes - Additional time: 2 hours = 120 minutes - Total school time: 300 + 30 + 120 = 450 minutes. **Step 3 — Bus time:** 510 − 450 = **60 minutes**. **Rule out wrong answers:** 90 (D) would ignore lunch or additional time; 30 (A) would count only one bus ride — but the round trip must be 60 minutes total. ANSWER 5: B # Problem 6: **What is asked:** Find the total number of students. **Step 1 — Set up equations.** Let g = number of girls, b = number of boys. Each boy gets b beans (b boys), each girl gets g beans (g girls): b² + g² = 400 − 6 = 394, and b = g + 2. **Step 2 — Substitute and solve:** (g+2)² + g² = 394 g² + 4g + 4 + g² = 394 2g² + 4g − 390 = 0 g² + 2g − 195 = 0 (g + 15)(g − 13) = 0 → g = 13 (reject −15). **Step 3 — Find the total:** Boys: b = 13 + 2 = 15. Total students = 15 + 13 = **28**. **Check:** 15² + 13² = 225 + 169 = 394 = 400 − 6. ✓ ANSWER 6: B # Problem 7: **What is asked:** Miles each of the 5 tires was used over 30,000 miles. **Step 1 — Total tire-miles used:** At any moment the car uses 4 tires. Over 30,000 miles, total tire-miles = 4 × 30,000 = 120,000. **Step 2 — Split equally among 5 tires:** 120,000 ÷ 5 = **24,000 miles** each. **Rule out wrong answers:** 30,000 (D) is wrong because no single tire can be used the whole time when 5 tires share the work; 6,000 (A) and 7,500 (B) wrongly divide by the wrong quantity (e.g., 30,000 ÷ 5 or ÷ 4). ANSWER 7: C # Problem 8: **What is asked:** Sum of the two two-digit multiples of 7 whose digits sum to 10. **Step 1 — List two-digit multiples of 7 and digit sums:** 14 (5), 21 (3), **28 (10)** ✓, 35 (8), 42 (6), 49 (13), 56 (11), 63 (9), 70 (7), 77 (14), 84 (12), **91 (10)** ✓, 98 (17). **Step 2 — Identify the two qualifying numbers:** 28 and 91. **Step 3 — Sum:** 28 + 91 = **119**. **Rule out wrong answers:** 126 (B) is 63 + 63 — impossible since numbers are distinct; 140 (D) might come from 28 + 112 (but 112 is three digits). ANSWER 8: A # Problem 9: **What is asked:** Ratio of Alex's can volume to Felicia's can volume. **Step 1 — Volume formula:** V = πr²h. **Step 2 — Alex's can:** diameter 6 → radius 3; height 12. V_A = π(3)²(12) = 108π. **Step 3 — Felicia's can:** diameter 12 → radius 6; height 6. V_F = π(6)²(6) = 216π. **Step 4 — Ratio:** V_A : V_F = 108π : 216π = **1 : 2**. **Rule out wrong answers:** 1:1 (C) is the tempting "swapped dimensions" intuition, but volume depends on the *square* of the radius, so doubling the radius quadruples that factor while halving the height only halves — net effect is Felicia's can is twice as big. ANSWER 9: B # Problem 10: **What is asked:** Find the smallest number > 2 that leaves remainder 2 when divided by 3, 4, 5, and 6, and identify the interval containing it. **Step 1 — Interpret the condition:** N − 2 must be divisible by 3, 4, 5, and 6, i.e., N − 2 is a multiple of LCM(3, 4, 5, 6). **Step 2 — Compute the LCM:** LCM(3,4,5,6) = 60 (since 60 is divisible by 3, 4, 5, and 6). **Step 3 — Candidates:** N = 60k + 2 for whole numbers k: N = 2, 62, 122, ... The smallest *greater than 2* is **62**. **Step 4 — Locate 62:** It lies between **61 and 65**. **Rule out wrong answers:** 42 + 2 = 44 is a common error (using 42, the LCM of only |
openrouter:qwen/qwen3.8-27b |
D | ✓ | showProblem 1:
The dress is originally priced at \$80. A 25% discount means the sale price is
\[
80(1-0.25)=80(0.75)=60.
\]
Then 10% tax is added to the sale price:
\[
60(1+0.10)=60(1.10)=66.
\]
So the total selling price is \$66.
ANSWER 1: D
Problem 2:
Anh drove 10 miles on the coastal road in 30 minutes, so his coastal-road speed was
\[
\frac{10\text{ miles}}{30\text{ minutes}}.
\]
He drove three times as fast on the highway. Therefore, for the same distance, the highway time would be one-third as long.
For 50 miles on the highway, if he had driven at coastal-road speed, it would take
\[
30 \times \frac{50}{10}=150
\]
minutes. But because he drove three times as fast on the highway, the actual highway time is
\[
\frac{150}{3}=50
\]
minutes.
The coastal road took 30 minutes, so the total trip time was
\[
30+50=80
\]
minutes.
ANSWER 2: C
Problem 3:
The equation should be read as
\[
2^w \cdot 3^x \cdot 5^y \cdot 7^z = 588.
\]
Factor 588:
\[
588=2\cdot 294=2^2\cdot 147=2^2\cdot 3\cdot 49=2^2\cdot 3^1\cdot 7^2.
\]
There is no factor of 5, so \(y=0\). Comparing prime exponents gives
\[
w=2,\qquad x=1,\qquad y=0,\qquad z=2.
\]
Now compute
\[
2w+3x+5y+7z=2(2)+3(1)+5(0)+7(2).
\]
\[
=4+3+0+14=21.
\]
ANSWER 3: A
Problem 4:
Let Pedro’s finishing time be \(P\). In a race, a smaller time means finishing earlier.
- Nico finished 11 minutes behind Pedro, so Nico’s time is
\[
P+11.
\]
- Olympia finished 3 minutes behind Pedro, so Olympia’s time is
\[
P+3.
\]
- Olympia finished 2 minutes ahead of Melina, so Melina’s time is
\[
(P+3)+2=P+5.
\]
- Olympia finished 6 minutes ahead of Luke, so Luke’s time is
\[
(P+3)+6=P+9.
\]
Now order the runners from first to last by increasing time:
\[
P,\quad P+3,\quad P+5,\quad P+9,\quad P+11.
\]
That is:
1. Pedro
2. Olympia
3. Melina
4. Luke
5. Nico
So the fourth runner was Luke.
ANSWER 4: A
Problem 5:
From 7:30 a.m. to 4:00 p.m. is 8 hours and 30 minutes:
\[
8(60)+30=480+30=510
\]
minutes.
Walter’s time in school not spent on the bus is:
- 6 classes of 50 minutes each:
\[
6(50)=300
\]
minutes;
- lunch: 30 minutes;
- additional time: 2 hours = 120 minutes.
Total non-bus time:
\[
300+30+120=450
\]
minutes.
So his total bus time was
\[
510-450=60
\]
minutes.
ANSWER 5: B
Problem 6:
Let the number of girls be \(g\). Since there were two more boys than girls, the number of boys is
\[
g+2.
\]
Mrs. Awesome gave each boy as many jelly beans as there were boys, so the boys received
\[
(g+2)^2
\]
jelly beans total. Each girl received as many as there were girls, so the girls received
\[
g^2
\]
jelly beans total.
She had 400 jelly beans and 6 left, so she gave away
\[
400-6=394.
\]
Thus,
\[
(g+2)^2+g^2=394.
\]
Expand:
\[
g^2+4g+4+g^2=394
\]
\[
2g^2+4g+4=394
\]
\[
2g^2+4g-390=0
\]
Divide by 2:
\[
g^2+2g-195=0.
\]
Factor:
\[
(g+15)(g-13)=0.
\]
Since \(g\) must be positive,
\[
g=13.
\]
Then the number of boys is
\[
13+2=15.
\]
The total number of students is
\[
13+15=28.
\]
ANSWER 6: B
Problem 7:
During the first 30,000 miles, the car was always using 4 tires at once. Therefore, the total “tire-miles” used is
\[
4 \times 30{,}000=120{,}000.
\]
There are 5 tires total, and they were all used the same number of miles. So each tire was used for
\[
\frac{120{,}000}{5}=24{,}000
\]
miles.
ANSWER 7: C
Problem 8:
We need two-digit multiples of 7 whose digits sum to 10.
The two-digit multiples of 7 are:
\[
14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84, 91, 98.
\]
Check digit sums:
\[
14: 1+4=5
\]
\[
21: 2+1=3
\]
\[
28: 2+8=10
\]
\[
35: 3+5=8
\]
\[
42: 4+2=6
\]
\[
49: 4+9=13
\]
\[
56: 5+6=11
\]
\[
63: 6+3=9
\]
\[
70: 7+0=7
\]
\[
77: 7+7=14
\]
\[
84: 8+4=12
\]
\[
91: 9+1=10
\]
\[
98: 9+8=17
\]
The only two are 28 and 91. Their sum is
\[
28+91=119.
\]
ANSWER 8: A
Problem 9:
The volume of a cylinder is
\[
V=\pi r^2h.
\]
Alex’s cans have diameter 6 cm, so radius 3 cm, and height 12 cm:
\[
V_A=\pi(3^2)(12)=\pi(9)(12)=108\pi.
\]
Felicia’s cans have diameter 12 cm, so radius 6 cm, and height 6 cm:
\[
V_F=\pi(6^2)(6)=\pi(36)(6)=216\pi.
\]
The ratio of Alex’s can volume to Felicia’s can volume is
\[
108\pi:216\pi=108:216=1:2.
\]
ANSWER 9: B
Problem 10:
Let the number be \(N\). It leaves a remainder of 2 when divided by 3, 4, 5, and 6, so
\[
N-2
\]
is divisible by 3, 4, 5, and 6. Therefore, \(N-2\) must be a multiple of the least common multiple of 3, 4, 5, and 6.
Find the LCM:
\[
\operatorname{lcm}(3,4,5,6)=60.
\]
So
\[
N-2=60k
\]
for some positive integer \(k\), because we need \(N>2\).
The smallest possible value is when \(k=1\):
\[
N-2=60
\]
\[
N=62.
\]
This lies between 61 and 65.
ANSWER 10: D |
openrouter:anthropic/claude-opus-5 |
D | ✓ | showProblem 1: Sale price: 25% off means you pay 75%: 80 × 0.75 = 60 dollars. Add 10% tax: 60 × 1.10 = 66 dollars. (Choice C, 54, would come from subtracting 10%; choice D is correct. Note taking 25% off then adding 10% doesn't return to 80.) ANSWER 1: D Problem 2: Coastal road: 10 miles in 30 minutes, so 3 minutes per mile. Highway speed is 3 times as fast, so 1 minute per mile. Highway time: 50 miles × 1 minute/mile = 50 minutes. Total: 50 + 30 = 80 minutes. (Choice A forgets the coastal 30 minutes; choice D would come from using 3 min/mile on the highway incorrectly.) ANSWER 2: C Problem 3: The equation is 2^w · 3^x · 5^y · 7^z = 588. Factor 588 = 4 · 147 = 2² · 3 · 7². So w = 2, x = 1, y = 0, z = 2. Then 2w + 3x + 5y + 7z = 2(2) + 3(1) + 5(0) + 7(2) = 4 + 3 + 0 + 14 = 21. ANSWER 3: A Problem 4: Let Pedro's time be 0 (he's a reference). - Nico = +11 - Olympia = +3 (3 min behind Pedro) - Melina = Olympia + 2 = +5 - Luke = Olympia + 6 = +9 Order from first: Pedro (0), Olympia (3), Melina (5), Luke (9), Nico (11). Fourth place is Luke. ANSWER 4: A Problem 5: Total time away: 7:30 a.m. to 4:00 p.m. = 8 hours 30 minutes = 510 minutes. Time at school: classes 6 × 50 = 300, lunch 30, extra 2 hours = 120; total 450 minutes. Bus time = 510 − 450 = 60 minutes (both trips combined). ANSWER 5: B Problem 6: Let g = number of girls, b = g + 2 boys. Jelly beans used: b² + g² = 400 − 6 = 394. (g + 2)² + g² = 394 → 2g² + 4g + 4 = 394 → g² + 2g − 195 = 0 → (g + 15)(g − 13) = 0 → g = 13. So girls = 13, boys = 15; check 169 + 225 = 394 ✓. Total students = 28. ANSWER 6: B Problem 7: Four tires are on the road at any time, so total tire-miles = 4 × 30,000 = 120,000. Shared equally among 5 tires: 120,000 ÷ 5 = 24,000 miles each. (30,000 would be if no rotation; 6,000 is the rest time per tire, not use.) ANSWER 7: C Problem 8: Two-digit multiples of 7: 14, 21, 28, 35, 42, 49, 56, 63, 70, 77, 84, 91, 98. Digit sums: 5, 3, 10, 8, 6, 13, 11, 9, 7, 14, 12, 10, 17. Digit sum 10 occurs for 28 and 91. Sum: 28 + 91 = 119. ANSWER 8: A Problem 9: Alex: diameter 6 → radius 3, height 12: V = π(3²)(12) = 108π. Felicia: diameter 12 → radius 6, height 6: V = π(6²)(6) = 216π. Ratio = 108π : 216π = 1 : 2. (Doubling the radius quadruples volume, while halving height only halves it, so Felicia's is twice as big — not equal.) ANSWER 9: B Problem 10: A number leaving remainder 2 when divided by 3, 4, 5, and 6 must be 2 more than a common multiple of 3, 4, 5, 6. LCM(3, 4, 5, 6) = 60, so the smallest such number greater than 2 is 60 + 2 = 62. 62 lies between 61 and 65. ANSWER 10: D |
openrouter:openai/gpt-5.6-terra-pro |
D | ✓ | showProblem 1:
The dress was originally priced at \$80.
A 25% discount means the sale price is \(75\%\) of the original price:
\[
80 \times 0.75=60
\]
Then 10% tax is added:
\[
10\% \text{ of } 60 = 6
\]
So the total price is
\[
60+6=66
\]
A common mistake is to subtract 25% and add 10% of the original \$80, but the tax is added to the reduced sale price, not the original price.
\[
\boxed{66}
\]
ANSWER 1: D
Problem 2:
Anh drove 10 miles on the coastal road in 30 minutes.
Since 30 minutes is \(\frac12\) hour, his coastal-road speed was
\[
\frac{10\text{ miles}}{\frac12\text{ hour}}=20\text{ miles per hour}
\]
He drove three times as fast on the highway:
\[
3(20)=60\text{ miles per hour}
\]
The highway trip was 50 miles, so the highway driving time was
\[
\frac{50}{60}\text{ hour}=\frac56\text{ hour}
\]
Convert \(\frac56\) hour to minutes:
\[
\frac56\cdot 60=50\text{ minutes}
\]
His total driving time was
\[
30+50=80\text{ minutes}
\]
The answer is not 50 minutes, since that is only the highway time.
\[
\boxed{80}
\]
ANSWER 2: C
Problem 3:
We are told that
\[
2^w\cdot 3^x\cdot 5^y\cdot 7^z=588
\]
Factor 588 into primes:
\[
588=2\cdot 294=2^2\cdot 147=2^2\cdot 3\cdot 49
\]
Thus,
\[
588=2^2\cdot 3^1\cdot 5^0\cdot 7^2
\]
So
\[
w=2,\qquad x=1,\qquad y=0,\qquad z=2
\]
Now calculate:
\[
2w+3x+5y+7z
\]
\[
=2(2)+3(1)+5(0)+7(2)
\]
\[
=4+3+0+14=21
\]
The factor \(5^0\) is important: since 588 has no factor of 5, \(y=0\), not 1.
\[
\boxed{21}
\]
ANSWER 3: A
Problem 4:
We compare all runners’ finishing times relative to Pedro.
- Nico finished 11 minutes behind Pedro.
- Olympia finished 3 minutes behind Pedro.
- Olympia finished 2 minutes ahead of Melina, so Melina finished 2 minutes behind Olympia.
- Olympia finished 6 minutes ahead of Luke, so Luke finished 6 minutes behind Olympia.
Let Pedro finish at time 0.
Then:
\[
\begin{array}{c|c}
\text{Runner} & \text{Minutes behind Pedro} \\
\hline
\text{Pedro} & 0\\
\text{Olympia} & 3\\
\text{Melina} & 3+2=5\\
\text{Luke} & 3+6=9\\
\text{Nico} & 11
\end{array}
\]
Therefore, the order is:
1. Pedro
2. Olympia
3. Melina
4. Luke
5. Nico
So Luke finished fourth.
\[
\boxed{\text{Luke}}
\]
ANSWER 4: A
Problem 5:
Walter is at school from 7:30 a.m. until 4:00 p.m.
That is:
\[
8\text{ hours }30\text{ minutes}=510\text{ minutes}
\]
His school-day activities take:
- 6 classes of 50 minutes each:
\[
6\cdot 50=300\text{ minutes}
\]
- Lunch:
\[
30\text{ minutes}
\]
- Additional school time:
\[
2\text{ hours}=120\text{ minutes}
\]
Total time not spent on the bus:
\[
300+30+120=450\text{ minutes}
\]
Therefore, bus time is
\[
510-450=60\text{ minutes}
\]
This includes both the ride to school and the ride home.
\[
\boxed{60}
\]
ANSWER 5: B
Problem 6:
Let the number of girls be \(g\).
There are two more boys than girls, so the number of boys is
\[
g+2
\]
Each boy receives as many jelly beans as there are boys, so the boys receive
\[
(g+2)(g+2)=(g+2)^2
\]
jelly beans altogether.
Each girl receives \(g\) jelly beans, so the girls receive
\[
g^2
\]
jelly beans altogether.
Mrs. Awesome gave away
\[
400-6=394
\]
jelly beans. Therefore,
\[
g^2+(g+2)^2=394
\]
Expand:
\[
g^2+g^2+4g+4=394
\]
\[
2g^2+4g-390=0
\]
Divide by 2:
\[
g^2+2g-195=0
\]
Factor:
\[
(g+15)(g-13)=0
\]
So
\[
g=13
\]
since a number of girls cannot be negative.
Thus boys:
\[
13+2=15
\]
Total students:
\[
13+15=28
\]
\[
\boxed{28}
\]
ANSWER 6: B
Problem 7:
During the first 30,000 miles, the car always uses 4 tires on the road.
So the total number of tire-miles used is
\[
4\cdot 30{,}000=120{,}000
\]
There are 5 tires total, and they were rotated so each tire was used equally.
Therefore, each tire was used
\[
\frac{120{,}000}{5}=24{,}000
\]
miles.
It is not 30,000 miles because only four of the five tires are being driven on at any one time.
\[
\boxed{24{,}000}
\]
ANSWER 7: C
Problem 8:
We need two-digit multiples of 7 whose digits add to 10.
The two-digit multiples of 7 are:
\[
14,21,28,35,42,49,56,63,70,77,84,91,98
\]
Check digit sums:
\[
28:\quad 2+8=10
\]
\[
91:\quad 9+1=10
\]
These are the only two.
Their sum is
\[
28+91=119
\]
\[
\boxed{119}
\]
ANSWER 8: A
Problem 9:
The volume of a cylinder is
\[
V=\pi r^2h
\]
For Alex’s can:
- Diameter \(=6\), so radius \(=3\)
- Height \(=12\)
\[
V_A=\pi(3)^2(12)=108\pi
\]
For Felicia’s can:
- Diameter \(=12\), so radius \(=6\)
- Height \(=6\)
\[
V_F=\pi(6)^2(6)=216\pi
\]
The ratio of Alex’s volume to Felicia’s volume is
\[
108\pi:216\pi
\]
Divide both parts by \(108\pi\):
\[
1:2
\]
Although Alex’s can is twice as tall, Felicia’s radius is twice as large, and radius is squared in the volume formula.
\[
\boxed{1:2}
\]
ANSWER 9: B
Problem 10:
We seek the smallest number greater than 2 that leaves remainder 2 when divided by 3, 4, 5, and 6.
If the number is \(n\), then \(n-2\) must be divisible by all of
\[
3,\ 4,\ 5,\ 6
\]
The least common multiple is
\[
\operatorname{lcm}(3,4,5,6)=60
\]
So the smallest possible value of \(n-2\) is 60:
\[
n-2=60
\]
\[
n=62
\]
The number 62 lies between 61 and 65.
Indeed:
\[
62\div 3,\ 62\div 4,\ 62\div 5,\ 62\div 6
\]
all leave remainder 2.
\[
\boxed{61\text{ and }65}
\]
ANSWER 10: D |