Question

A bag contains 7 red marbles, 8 blue marbles, and 5 green marbles. Mara randomly chose a marble, then she put it back and randomly chose another marble. What is the probability that she chose 2 blue marbles? Answers in decimal form please.

Answer 1

7 + 8 + 5 = 20 total marbles

8 blue

probability of picking a blue marble = 8/20, reduces to 2/5 = 0.40

since she puts the first marble back, the 2nd pick is the same probability as the first one

so the probability of picking 2 blue would be 0.40 x 0.40 = 0.16