Question

There are 5 red marbles, 15 blue marbles, and 5 green marbles in a bag. If you reach in and randomly draw two marbles without replacing the first, what is the probability that both will be blue?

A.8/15
B.3/5
C.19/49
D.7/20

Answer 1

7/20

Explanation:

This is a dependent event, which means the first event will affect the probability of the second event.

First, you need to find the probability of the first event, in this case, 3/5 (this is because out of 25 marbles in total, there are 15 blue ones. 15/25 reduces to 3/5).

Now you need to find the probability of the second event, which changes because you have already taken a blue marble out of the bag. So instead of having 15 blue marbles, you now have 14. And instead of 25 total marbles, you now have 24. 14/24 reduces to 7/12.

Now that you have both probabilities, you just need to multiply.

3/5 x 7/12 = 7/20.

So 7/20 will be your final answer.

Answer 2

The answer is B 3/5 because 15/25 is simplified to 3/5

divide both 15/25 by 15 and you get 3/5