Question

A bag contains 2 red, 5 blue, and 2 white marbles. Find the probability of randomly picking a red marble, keeping the marble, and then picking a blue marble.

A) 7/8

B) 10/81

C) 5/36

D) 1/9

Answer 1

5/36

Explanation:

There are 9 marbles in the bag

P( red) = number of red / total

= 2/9

Keep the marble

1 red, 5 blue, and 2 white = 8 marbles

P( blue) = number of blue / total

= 5/8

P(red, keep,blue) = 2/9 * 5/8 = 10/72 = 5/36