Mettl Quantitative Aptitude 3 — Questions and Answers
Question 1: A pipe can fill a tank in 12 hours. Another pipe can empty it in 18 hours. If both pipes are open simultaneously, how many hours will it take to fill the empty tank?
- 36 hours (Correct answer)
- 30 hours
- 24 hours
- 6 hours
Correct answer: 36 hours
Net fill rate = 1/12 - 1/18 = 1/36, so the tank fills in 36 hours.
Question 2: The simple interest on $4,000 at 6% per annum for 3 years is:
- $720 (Correct answer)
- $480
- $820
- $540
Correct answer: $720
SI = P × R × T / 100 = 4000 × 6 × 3 / 100 = $720.
Question 3: In a class of 40 students, the average score is 72. If the top 10 students have an average of 90, what is the average of the remaining 30 students?
- 66 (Correct answer)
- 68
- 70
- 64
Correct answer: 66
Total = 40×72 = 2880; top 10 total = 900; remaining = (2880−900)/30 = 66.
Question 4: A shopkeeper marks a product 40% above cost price and offers a 20% discount. What is his profit percentage?
- 12% (Correct answer)
- 20%
- 8%
- 16%
Correct answer: 12%
SP = 140% × 80% = 112% of CP, giving a 12% profit.
Question 5: If 3x + 7 = 22, what is the value of 6x − 4?
- 26 (Correct answer)
- 30
- 22
- 18
Correct answer: 26
3x = 15, so x = 5; then 6(5) − 4 = 26.
Question 6: A train 200 m long passes a pole in 10 seconds. How long will it take to pass a 300 m long platform?
- 25 seconds (Correct answer)
- 20 seconds
- 15 seconds
- 30 seconds
Correct answer: 25 seconds
Speed = 200/10 = 20 m/s; distance = 200+300 = 500 m; time = 500/20 = 25 s.
Question 7: What is the least common multiple (LCM) of 18, 24, and 36?
- 72 (Correct answer)
- 36
- 144
- 108
Correct answer: 72
Prime factorization gives LCM = 2³ × 3² = 72.
Mettl Quantitative Aptitude 3
A pipe can fill a tank in 12 hours.
Another pipe can empty it in 18 hours.
If both pipes are open simultaneously, how many hours will it take to fill the empty tank?