The number of different words that can be formed with the letters of the word 'MISSISSIPPI', is

There are 11 letters in the given word, of which 4 are S′s,4 are I′s and 2 are P's. So, total number of words is the number of arrangements of 11 things, of which 4 are similar of one kind, 4 are similar of second kind and 2 are similar of third 11!4!4!2!Hence, the total number of words =11!4!4!2!