Question

A bag contains 9 marbles: 4 are green, 3 are red, and 2 are blue. Susan chooses a marble at random, and without putting it back, chooses another one at random. What is the probability that both marbles she chooses are blue? Write your answer as a fraction In simplest form.​

Answer 1

The probability of picking blue is the number of blue marbles/ total marbles.

For the first pick there are 2 blue marbles and 9 total marbles so the probability of picking blue would be 2/9

After picking the first marble there would be 1 blue marble left and 8 total marbles. The probability of picking the blue marble would be 1/8

To find the probability of picking both, multiply the probability of each one by each other:

2/9 x 1/8 = 2/72, which reduces to 1/36

The answer is 1/36