A bag contains 2 blue, 1 red, and 3 green marbles. You choose one marble. Without
putting it back, you choose a second marble.
What is the probability that you first choose a green marble and then a blue marble?
P(green then blue) = 1/15
P(green then blue) = 1/5
P(green then blue) = 1/6
P(green then blue) = 2/5