Question

A bag contains 6 red marbles, 3 blue marbles and 7 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 red?

Answer 1

Answer: 0.036

Work Shown:

6 red, 6+3+7 = 16 total

A = 6/16 = probability of getting red the first time

after you pick 1 red, there's 6-1 = 5 left out of 16-1 = 15 total

B = 5/15 = probability of getting red the second time

then you repeat: 5-1 = 4 red left out of 15-1 = 14 total

C = 4/14 = probability of getting red the third time

B and C are dependent on A, C is dependent on B. This is assuming we do not put any marbles back.

Multiply out the fractions found

A*B*C = (6/16)*(5/15)*(4/14) = 0.0357 which rounds to 0.036 when rounding to the nearest thousandth.