Question

How many different 10-letter permutations can be formed from 8 identical H's and two identical T's?

Answer 1

45 different permutations

Explanation:

Given 10 letters with 8 identical H's and two identical T's, the number of different permutations will be expressed as;

`= (10!)/(8!2!)`

`= (10*9*8!)/(8!*2!)\\ \\= (10*9)/(2*1)\\ \\= (90)/(2)\\ \\= 45`

Hence the number of different 10-letter permutations that can be formed from 8 identical H's and two identical T's is 45