A bag contains 7 red marbles, 5 blue marbles and 4 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

Pr(3R) = 7/16 x 6/15 x 5/14 = (7)(6)(5)/(16)(15)(14) = 6x5/16x15x2 = 5/16x5= 1/16 = (1/2)(.125) = 0.0625

Probability of 3 reds = 0.0625

round off to thousandths Pr(3R) = 0.063