Question

A box contains 7 green marbles, 10 blue marbles, and 5 red marbles. Three marbles are selected at random from the box, one at a time, without replacement. Find the probability that two of the marbles selected are green and the other marble is red.

Answer 1

5/253

Explanation:

The first green is 7/23, the second is 6/22 and the red is 5/21. Multiply them together for 5/253.