Question

How many combinations of four books can be made from eight different books? 24 70 1,680?

Answer 1

Answer:

70

Step-by-step explanation:

four books can be made from eight different books

4 books to be chosen from 8 books

The order does not matters so we use Combination.

four books can be made from eight different books, so we find 8C4

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

$8C4= \frac{8!}{4!(8-4)!}$

$8C4= \frac{8!}{4!(4)!}$

$8C4= \frac{8*7*6*5*4!}{4!(4)!}=70$