Question:
In how many ways can the letters of the word ‘ASSASSINATION’ be arranged so that all S’s are together?
Solution:
To find: number of ways letters can be arranged such that all S’s are together
Let all S’s be represented by a single letter Z
New word is AAINATIONZ
Number of arrangements $=\frac{10 !}{3 ! 2 ! 2 !}=151200$
Letters can be arranged in 151200 ways