Question

Suppose that you want to buy 6 different books and the order that you buy them does not matter. Then thenumber of ways to choose 6 books from 44 available books is

Answer 1

We have that the order doesn't matter without repetition, so should use combinations that are represented by the next formula:

$C=\frac{n!}{r!(n-r)!}$

Where n is the total of books and r the numbers of the group, in this case, 6 differents books.

Replace these values:

$\frac{44!}{6!(44-6)!}$$C=\frac{44!}{6!(38)!}=7059052\text{ ways to choose 6 books from 44 available}$