Question

Find the number of different ways that the 9 letters of the word happiness can be arranged in a line

Answer 1

hat mate it is your answer
9 letter can be arrange by= factorial 9
. . . =362880

Answer 2

The number of letters is 9, hence we do 9!

however, there are 2 letters which are repeated twice, 2!*2!

so the answer is 9!/2!2!

which gives us 90720