Answer: 56
To solve this problem, we will use the formula for Combination which goes by
[tex]_{}C(n,r)=^nC_r=_nC_r=\frac{n!}{r!(n-r)!}[/tex]From the problem, we know that:
n = 8
r = 3
Since there are a total of 8 different movie soundtracks and we only need 3.
Substituting it on the formula,
[tex]C(n,r)=\frac{n!}{r!(n-r)!}[/tex][tex]C(8,3)=\frac{8!}{3!(8-3)!}[/tex][tex]C(8,3)=56[/tex]Therefore, there are 56 possible selections of movie soundtracks at the music store.
