Hawks Learning 7.4 for finite math

Question

A bag of 11 marbles contains 7 marbles with red on them, 4 with blue on them, 5 with green on them, and 5 with red and green on them. What is the probability that a randomly chosen marble has either green or red on it?

Answer 1

Thank you for your question!

The question wants you to find the P(R or G) … in order to compute that we want to start with finding how many scenarios there are where it could be red or green or both.

The formula for that is to take Total Red + Total Green and then subtract the overlap that are in both so that we’re not double counting, so that becomes 7 + 5 – 5 = 7.

Then since there are 11 marbles in total you can just divide to find the end probability of 7/11 :)