A bag contains 7 red marbles, 2 blue marbles and 3 green marbles. If two marbles are drawn out of the bag, what is the exact probability that both marbles drawn will be blue?

Answer 1

The total number of marbles in the bag is 7+2+3=12.

The probability of drawing a blue marble on the first draw is 2/12.

After the first marble is drawn, there are 11 marbles remaining in the bag, including 1 blue marble out of 2 remaining.

So the probability of drawing a second blue marble is 1/11.

To find the probability of both events happening (drawing two blue marbles), we multiply the probabilities:

P(drawing two blue marbles) = (2/12) x (1/11)

= 1/66

Therefore, the exact probability that both marbles drawn will be blue is 1/66.