Question

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

Answer 1

Answer:

45 different permutations

Step-by-step explanation:

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

$= \dfrac{10!}{8!2!}$

$= \dfrac{10*9*8!}{8!*2!}\\ \\= \dfrac{10*9}{2*1}\\ \\= \dfrac{90}{2}\\ \\= 45$

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