Question

A box contains 12 balls of which 5 are red, and 7 are blue. If 4 balls are drawn from the box, in how many ways can this be done if 1 is red and 3 are blue?

Answer 1

175 ways

Explanation:

5 balls are red, and 7 balls are blue making a total of 12 balls.

4 balls are drawn from the box,

1 ball is red and 3 balls are blue out of the 4 drawn from the box.

We have to choose 1 ball from 5 red balls and 3 blue balls from 7 blue balls.

Since the order is not essential we use combinations to find out

5C1 * 7C3= 5*35 = 175 ways