AFCAT Numerical Ability & Quantitative Aptitude 3

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?

Accepted Answer

1.5 km/h

Answer

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?

Accepted Answer

12 min

Answer

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?

Accepted Answer

3^(-1)

Answer

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?

Accepted Answer

32 years

Answer

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?

Accepted Answer

33

Answer

The middle (3rd) odd number equals the average = 29; so the five numbers are 25, 27, 29, 31, 33 and the largest is 33.

(AFCAT) Air Force Common Admission Test Practice Test

(AFCAT) Air Force Common Admission Test Practice Test

AFCAT Numerical Ability & Quantitative Aptitude 3