Question

A student has 6 black marbles and 2 red marbles in his pocket. He selects one marble at random, looks at it and puts it back. Then he will select another marble at random. What is the probability that the student selects black marbles both times?

Answer 1

Total marbles = 6 + 2 = 8

p(black) = 6/8 = 3/4

p(both black) = 3/4 x 3/4 = 9/16

Answer: 9/16