Question

A bag contains 5 red marbles, 6 blue marbles and 9 yellow marbles.

What is the probability of picking out a red marble, putting in back in the bag, and then picking out a yellow marble?
What is the probability of picking out a blue marble, putting it in your pocket, and picking out another blue marble?

Answer 1

Explanation:

The total number of marbles is 20

Question A

P(Red) = 4/20 = 1/5

P(yellow) = 9/20

P(Red then Yellow) = 1/5 * 9/20 = 9 / 100

Question B

P(B) = 6/20

P(B again) = 5/19 because you have 1 less total plus 1 less blue.

P(B and B) = 6/20 * 5/19

P(B and B) = 30/ 380 = 3/38