Aileen wants 2 green marbles. What is the probability she will draw 2 green marbles at random if she replaces the first marble before she draws the second marble? (there is a total of 10 marbles, there are 5 green, 4 blue, and 1 red)

Of the 10 marbles in the container, 5 are green. So if Aileen doesn't peek,

her chance of drawing a green marble is 5/10 or 0.5.

The chance that she will draw a green marble the first time is 0.5.

The chance that she will draw a green marble the second time is 0.5.

The probability that she will draw a green marble both times is

(0.5) x (0.5) = 0.25 or 25 percent.