If the letters of the word ASSASSINATION are arranged at random. Find the Probability that
(a) Four S’s come consecutively in the word
(b) Two I’s and two N’s come together

Solution:

The given word is ASSASSINATION

Total no. of letters in ASSASSINATION

In the given word ASSASSINATION, there are 3A’s, 4S’s, 2I’s, 2N’s, 1T’s and 1O’s

The total no. of ways in which these letters can be arranged
(a) Four S’s come consecutively in the word
If s comes consecutively then the word ASSASSINATION become.
Therefore, now the no. of letters is

We can write the above equation as


(b) Two I’s and two N’s come together
Therefore, now no. of letters is

The required Probability
We can write the above equation as