Question

An experiment consists of randomly selecting a marble from a bag, keeping it, and then selecting another marble. The bag contains 4 blue marbles, 3 green marbles, 7 red marbles, and 1 yellow marble. What is the probability of selecting a red marble and then a blue marble? SHOW ALL WORK!

Answer 1

2/15

Explanation:

How many marbles are in the bag

4blue + 3 green + 7 red + 1 yellow = 15 marbles

On the 1st draw:

red/total = 7/15

Since we keep the marble, there are only 14 marbles left

4blue + 3 green + 6 red + 1 yellow = 14

On the 2nd draw:

blue/total = 4/14 = 2/7

To find the probability of the two draws, we multiply them together

1st draw * 2nd draw

7/15 * 2/7 = 2/15