How many ways can you choose 1 red ball?

Question

A bag contains 9 red balls and 6 white balls. Suppose we choose 3 random balls. How many ways can we choose exactly 1 red ball?

Answer 1

A bag contains 9 red balls and 6 white balls .

Suppose we choose 3 random balls.

Number of ways to select 1 red ball : 9

Number of ways to select 2 white balls : 

Number of ways when select 3 balls to select 1 red ball : .

Solution : 135 ways we can choose exactly 1 red ball.