How many ways are there to select 3 of 15 flavors of juice at the grocery store?

First, you need to distinguish if this is a permutation or a combination. The difference between the two is the order. In combination, order does not matter. Since there is no any restriction given, we assume this is a combination problem. The equation of determining the number of ways to choose 'r' objects out of total 'n' objects is:

Number of ways = n!/r!(n-r)! = 15!/3!(15-3)! = 455

There are 455 ways.

Distributive property