Question
In how many ways can the letters of word ‘ASSASSINATION’ be arranged so that all the S’s are together?
Solution
Number of letters:
A → 3, S → 4
I → 2, N → 2
T → 1, O → 1
Total letters 13.
Tie the 4 S's.
Number of permutations = 
Mix with remaining to give:
[3 (A) + 2 (I) + 2 (N) + 1 (T) + 1 (O)] + 1 = 10.
Number of arrangements = 
Total number of arrangements = 1 x 151200 = 151200.
