A bag of marbles contains 2 blue, 5 green, and 3 red marbles. If you take out 2 marbles, what is the probability that they are both green? (Enter your probability as a fraction.)

Question

A bag of marbles contains 2 blue, 5 green, and 3 red marbles. If you take out 2 marbles, what is the probability that they are both green?

Answer 1

Well there are 10 marbles so we can pick the marbles in 10 C 2 ways

If both are green we can pick the greens in 5 C 2 ways as there are 5 greens

So 5 C 2 / 10 C 2