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:

He can choose 3 marbles from 7 distinct marbles in (7/3) ways

C(7/3) = 7!/(3!-(7-3)!)

= 7*6*5*4/4*3*2

= 35

Answer 2

35

Explanation:

Use the combination formula:

`C(n,r)=(n!)/(r!(n-r)!)`

Substitute known values:

`C(7,3)=(7!)/(3!(7-3)!)=35`

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