AFCAT Numerical Ability & Quantitative Aptitude 3 — Questions and Answers
Question 1: A boat travels 36 km upstream in 4 hours and 48 km downstream in 4 hours. What is the speed of the current?
- 1.5 km/h (Correct answer)
- 2 km/h
- 3 km/h
- 2.5 km/h
Correct answer: 1.5 km/h
Upstream speed = 9 km/h, downstream speed = 12 km/h; current = (12-9)/2 = 1.5 km/h.
Question 2: Two pipes A and B can fill a tank in 20 minutes and 30 minutes respectively. If both are opened together, in how many minutes will the tank be filled?
- 10 min
- 12 min (Correct answer)
- 15 min
- 25 min
Correct answer: 12 min
Combined rate = 1/20 + 1/30 = 5/60 = 1/12; tank fills in 12 minutes.
Question 3: What is the value of 3^4 x 3^(-2) divided by 3^3?
- 3^(-1) (Correct answer)
- 3^0
- 3^1
- 3^2
Correct answer: 3^(-1)
3^4 x 3^(-2) / 3^3 = 3^(4-2-3) = 3^(-1).
Question 4: A sum of money doubles itself in 8 years at simple interest. In how many years will it become 5 times itself?
- 24 years
- 32 years (Correct answer)
- 36 years
- 40 years
Correct answer: 32 years
Rate = 100/8 = 12.5% per year; to become 5 times, SI = 4P; t = 4x100/12.5 = 32 years.
Question 5: The average of 5 consecutive odd numbers is 29. What is the largest of these numbers?
- 31
- 33 (Correct answer)
- 35
- 37
Correct answer: 33
The middle (3rd) odd number equals the average = 29; so the five numbers are 25, 27, 29, 31, 33 and the largest is 33.
Question 6: If 30% of A is equal to 40% of B, then A:B is:
- 3:4
- 4:3 (Correct answer)
- 2:3
- 3:2
Correct answer: 4:3
0.3A = 0.4B gives A/B = 0.4/0.3 = 4/3.
Question 7: A rectangle has length 18 m and perimeter 54 m. What is the area of the rectangle?
- 108 m^2
- 162 m^2 (Correct answer)
- 180 m^2
- 216 m^2
Correct answer: 162 m^2
Width = (54/2) - 18 = 27 - 18 = 9 m; area = 18 x 9 = 162 m^2.
AFCAT Numerical Ability & Quantitative Aptitude 3
A boat travels 36 km upstream in 4 hours and 48 km downstream in 4 hours.
What is the speed of the current?