Question

The number if marbles of different colors stored in a hat is listed below: 4 red marbles 10 green marbles 7 blue marbles. Without looking in the hat, dan takes out a marble at random. He replaces the marble and then takes out another marble from the hat. What is the probability that dan takes out a blue marble in both draws?

Answer 1

1/9

Explanation:

There are a total of 21 marbles. In the first draw, there are 7 blue marbles out of 21. In the second draw, since he replaces the marble, there are still 7 blue marbles out of 21. So the probability is:

P = (7/21)²

P = 1/9