Q.11. In how many ways can the letters of the word ASSASSINATION be arranged
so that all the S’s are together?
In the word ASSASSINATION, we have
number of S =4
number of A =3
number of I= 2
number of N =2
Rest of letters appear at once.
Since all words have to be arranged in such a way that all the S are together so we can assume SSSS as an object.
The single object SSSS with other 9 objects is counted as 10.
These 10 objects can be arranged in (we have 3 A's,2 I's,2 N's)
Hence, requires the number of ways of arranging letters