PrepRung

CAT 2018 Slot 1 · Quant · Permutations, Combinations and Sets · medium

In how many ways can the letters of the word ELEVEN be arranged so that no two E's are next to each other?

Single correct option

In how many ways can the letters of the word ELEVEN be arranged so that no two E's are next to each other?
  1. A. 24
  2. B. 18
  3. C. 30
  4. D. 20
Show answer and solution

Answer: (A) 24

First arrange the other letters L, V, N (all distinct): 3! = 6 ways.

These three letters create 4 gaps (including both ends). Place the three identical E's in three different gaps: C(4, 3) = 4 ways.

Total = 6 × 4 = 24.

Check by complement: Total arrangements = 6!/3! = 120 (E repeats 3 times); direct enumeration of the no-two-E-adjacent case confirms 24.
Report a mistake

Original question written in the CAT 2018 Slot 1 pattern and checked twice for the correct answer. Not an official question paper. How we write and check questions · Corrections policy · Report a mistake