AFCAT Numerical Ability & Quantitative Aptitude 4 — Questions and Answers
Question 1: A man sells two articles at Rs. 990 each. On one he gains 10% and on the other he loses 10%. His overall gain or loss percent is:
- 1% gain
- 1% loss (Correct answer)
- No gain/loss
- 2% loss
Correct answer: 1% loss
When selling at the same price with equal % gain and loss, there is always a net loss of (common%)^2 / 100 = 1%.
Question 2: Find the next term in the series: 2, 6, 18, 54, ___
- 108
- 162 (Correct answer)
- 216
- 270
Correct answer: 162
Each term is multiplied by 3; 54 x 3 = 162.
Question 3: If (x + 1/x) = 5, what is the value of (x^2 + 1/x^2)?
- 23 (Correct answer)
- 25
- 27
- 21
Correct answer: 23
x^2 + 1/x^2 = (x + 1/x)^2 - 2 = 25 - 2 = 23.
Question 4: A sum amounts to Rs. 6,050 in 2 years and Rs. 6,655 in 3 years at compound interest. What is the rate of interest?
- 8%
- 10% (Correct answer)
- 12%
- 15%
Correct answer: 10%
Rate = (6655 - 6050) / 6050 x 100 = 605/6050 x 100 = 10%.
Question 5: The volume of a cube is 729 cm^3. What is the total surface area of the cube?
- 324 cm^2
- 486 cm^2 (Correct answer)
- 540 cm^2
- 648 cm^2
Correct answer: 486 cm^2
Side = cube root of 729 = 9 cm; total surface area = 6 x 9^2 = 6 x 81 = 486 cm^2.
Question 6: Two numbers are in the ratio 3:5. If 8 is subtracted from each, the ratio becomes 1:3. What is the larger number?
- 10
- 15
- 20 (Correct answer)
- 25
Correct answer: 20
Let numbers be 3x and 5x; (3x-8)/(5x-8) = 1/3 gives 9x-24 = 5x-8, x = 4; larger = 5x4 = 20.
Question 7: A person covers 40% of a journey at 60 km/h and the remaining 60% at 90 km/h. What is his average speed for the whole journey?
- 72 km/h
- 75 km/h (Correct answer)
- 78 km/h
- 80 km/h
Correct answer: 75 km/h
Let total = 100 km; time = 40/60 + 60/90 = 2/3 + 2/3 = 4/3 h; avg speed = 100 / (4/3) = 75 km/h.
AFCAT Numerical Ability & Quantitative Aptitude 4
A man sells two articles at Rs. 990 each.
On one he gains 10% and on the other he loses 10%.
His overall gain or loss percent is: