Question

What is the probability that for S's come consecutively in the word "MISSISSIPPI" ?

Answer 1

The total number of arrangements of the letters of the word "MISSISSIPPI" is

$\frac{11!}{4!4!2!}$

Considering 4 S's as one letter, there are 8 letters which can be arranged in arrow in $\frac{8!}{4!2!}$ ways.

So, the number of ways in which 4 S's come together = $\frac{8!}{4!2!}$.

Hence, required probability = $\frac{8!/4!2!}{11!/4!4!2!}=\frac{8!\times 4!}{11!}=\frac{4}{165}$