Permutation and Combination aptitude questions
Permutation and Combination questions are part of the Quant section of placement aptitude tests. Decide whether order matters before choosing arrangement or selection. Below are 5 worked examples with the answer and the working; practise ten fresh ones or take a timed mock when you are ready.
Example 1. How many distinct arrangements can be made using all the letters of the word MANGO?
- A. 60
- B. 120 (answer)
- C. 144
- D. 24
All 5 letters are distinct, so the count is 5! = 120.
Example 2. In how many ways can 2 people be seated in 6 distinct chairs, one person per chair?
- A. 30 (answer)
- B. 12
- C. 33
- D. 15
Order matters here, so use permutations: nPr = 6!/(6 - 2)! = 30.
Example 3. In how many ways can a committee of 3 be chosen from 8 people?
- A. 56 (answer)
- B. 168
- C. 11
- D. 336
Order does not matter, so use combinations: nCr = 8!/(3! * 5!) = 56.
Example 4. In how many ways can a committee of 4 be chosen from 7 people?
- A. 35 (answer)
- B. 140
- C. 840
- D. 11
Order does not matter, so use combinations: nCr = 7!/(4! * 3!) = 35.
Example 5. In how many ways can a committee of 3 be chosen from 9 people?
- A. 504
- B. 84 (answer)
- C. 12
- D. 252
Order does not matter, so use combinations: nCr = 9!/(3! * 6!) = 84.
More Quant practice elsewhere: IndiaBIX, GeeksforGeeks. See the 60-day aptitude plan.