Consider all possible permutations of the letters of the word ENDEANOEL. The number of permutations in which the letter E occurs in the first and last positions is

Options

A. 5!
B. `2xx5!`
C. `7xx5!`
D. `21xx5!`

Explanation

There are 3E's out of which two are fixed at first and least position. After fixing two E's 7 letters are left which can be permuted in `(7!)/(2!)` ways i.e., `21xx5!` ways.
`:.` Required number of permutations `=21xx5!`