Question

How much number of ways of permuting letters are there of the word ENDEANOEL son that none of the letters D, L, N occurs in the last five position ?

Answer 1

Given word ENDEANOEL

Total letters $9$, out of which E's are $3$, N's are $2$ consider DNNL as $1$ set this can arranged in $\frac{4!}{2!}=12$ ways

Rest $5$ can be arrange in $\frac{5!}{3!}=5\times 4=20$ ways

$\therefore$ Total $12\times 20$

$=240$ways.