Respuesta :
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
[tex]nCr= \frac{n!}{r!(n-r)!}[/tex]
[tex]8C4= \frac{8!}{4!(8-4)!}[/tex]
[tex]8C4= \frac{8!}{4!(4)!}[/tex]
[tex]8C4= \frac{8*7*6*5*4!}{4!(4)!}=70[/tex]