Find the number of words formed by permuting all the letters of the following word: SERIES

Explanation

There are `6` letters in the word ‘SERIES’ out of which `2` are S’s, `2` are E’s and the rest all are distinct.

The total number of arrangements = `(6!) / (2! 2!)

= [6 × 5 × 4 × 3 × 2 × 1] / (2! 2!)
= 6 × 5 × 3 × 2 × 1 = 180`