Question

Johnny has 7 different colored marbles in his bag. In how many ways can he choose three different marbles from his bag to play a game?

Answer 1

Answer:

35

Step-by-step explanation:

Use the combination formula:

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

Substitute known values:

$C(7,3)=\frac{7!}{3!(7-3)!}=35$

We don't use the permutation formula since the order of the drawn marbles does not matter.