Question

In how many ways can the letters of the word STORY be arranged, so that
i.T and Y are always together?ii. T is always next to Y?

Answer 1

STORY

(i) T & Y are always together

TY SRO

No of ways$=4!2!$

$4!\to$ Inter permutation between S, R, O, TY

$2!\to$ Intra permutation between T & Y

(ii) T is always next to Y

YT SRO

No. of ways$=4!$ (Intra permutation between Y and T is not possible here as the order is fixed).