Question

You have 3 red marbles, 5 green, and 2 blue marbles. What is the probability of pulling a blue marble and then replacing the first marble and then grabbing a green marble?
(As a percent)

Answer 1

Answer:

I think it's $\frac{7}{10}$.

Why 7/10?

Well, the probability of pulling out a blue marble + pulling out a green marble is also written as $\frac{2}{10} +\frac{5}{10}=\frac{7}{10}$