A bag contains 7 red marbles, 4 blue marbles and 5 green marbles. If two marbles are drawn out of the bag, what is the exact probability that both marbles drawn will be blue?
The probability that both marbles will be blue is because your probability of drawing a blue marble (3/5) multiplied by my probability of drawing a red marble (4/9): 3/5 x 4/9 = 12/45 or, reduced, 4/15.
