Question

A bag contains 3 red marbles, 5 blue marbles and 6 green marbles. If three marbles are drawn out of the bag, what is the probability, to the nearest 1000th, that all three marbles drawn will be blue?

Answer 1

0.027 to the nearest thousandth.

Explanation:

There are 14 marbles in the bag, so:

Prob( a blue on the first draw) = 5/14.

Prob( a blue on the 2nd draw) = 4/13.

Prob( a blue on the 3rd draw) = 3/12 = 1/4.

So the required probability is 5/14 * 4/13 * 1/4

= 20/ 728

= 0.02747.