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

11 marbles

7 red, 4 blue 5 green

5 red & green

probability a randomly chosen marble has red or green on it:

4 blue, 11-4 = 7 that are red or green or red&green

Pr (red or green or both) =7/11 = 63.6363..%