Consider the word ASSASSINATION.
How many different ways can be arranged so that the 4S's come together?

Explanation

There are 13、etters, including four .S.s, three .A. s, two I.s, two "N.s: By taking four.S.s together, there are 10 letters (four .S. taken as one unit)
These 10 letters can be arranged in `10 !/3 ! 2 ! 2 !` ways.
The number of arrangements `=.10 !/3 ! 2 ! 2 !=151200`