A bag contains 2 red marbles, 7 blue marbles and 8 green marbles. If two marbles are drawn out of the bag, what is the exact probability that both marbles drawn will be blue?
There are a total of 17 marbles in the bag.
The probability of drawing a blue marble on the first draw is 7/17.
After the first blue marble is drawn, there are only 6 blue marbles left out of 16 total marbles.
Therefore, the probability of drawing a second blue marble after the first one is 6/16.
Multiplying these probabilities gives:
(7/17) x (6/16) = 21/136
Therefore, the exact probability that both marbles drawn will be blue is 21/136.