Question

A jar contains 28 marbles. It has 10 red, 8 black and 10 green marbles. Two marbles are drawn, the first is not returned before the second one is drawn. What is the probability that both marbles are green?

Answer 1

P(green) first drawn:
10/28=5/14
P(green) second drawn:
9/27=1/3
As a result, probability that both marbles are green is 5/42. Hope it help!