Question

The number of words, with or without meaning, that can be formed by taking 4 letters at a time from the letters of the word 'SYLLABUS' such that two letters are distinct and two letters are alike is ______.

पर्याय

• 220

• 230

• 240

• 250

Answer 1

The number of words, with or without meaning, that can be formed by taking 4 letters at a time from the letters of the word 'SYLLABUS' such that two letters are distinct and two letters are alike is 240.

Explanation:

S ${\displaystyle \to }$ 2, L ${\displaystyle \to }$ 2, A, B, Y, U.

∴ Required number of ways = ${\displaystyle {}^2{C}_1\times {}^5{C}_2\times \frac{4!}{2!}}$ = 240.