Numerical Ability Reviewer - Part 3

Practice 20 Numerical Ability questions for the Civil Service Exam (CSE), each with the correct answer and an explanation.

20 questions80% passing markFree

Part 3 of our Numerical Ability reviewer has 20 practice questions in the style of the Civil Service Exam. Answer them in order, read the explanation after each one, and check your score against the 80% passing mark at the end. Questions and choices are reshuffled every time you retake the part.

Start Part 3

Sample questions from Part 3

Here are a few questions from this part. Take the full test to answer all 20 and get your score.

Sample question 1

Radicals: √0.000025

  • 0.5
  • 0.005
  • 0.0005
  • 0.00005
Answer: 0.005
Radicals: √0.000025 = √(25/1000000)
= 5/1000 = 0.005

Sample question 2

Number Series: 1/12, 1/6, 1/4, 1/3, ____

  • 1
  • 1/3
  • 5/12
  • 1/2
Answer: 5/12
1/12, 1/6, 1/4, 1/3, ____
1/12, 2/12, 3/12, 4/12, 5/12

Sample question 3

A chemist has 400 milliliters of a solution of 20% alcohol on hand, and he wants to mix it with
enough pure alcohol to turn it into a 30% alcohol solution. How much pure alcohol will this require?

  • 30
  • 40
  • 50
  • 57
Answer: 57
20%(400)+100%N = 30%(400+N) ignore percentage
8000+100N=12000+30N
100N-30N = 12000-8000
70N=4000
N = 4000/70 = 57.14

Sample question 4

What is the percentage decrease from 80 to 60?

  • 33.33%
  • 25%
  • 20%
  • 75%
Answer: 25%
= Amount decrease/original amount × 100%
= (80-60)/80 = 20/80= 0.25×100% = 25%

Sample question 5

What is the percentage increase from 60 to 80?

  • 33.33%
  • 25%
  • 20%
  • 75%
Answer: 33.33%
= Amount increase/original amount × 100%
= (80-60)/60=20/60 = 0.3333×100% = 33.33%

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