A bag has 9 red marbles and 6 green marbles. How do you find the probability of drawing a green marble, replacing it, and drawing another green marble?

1 Answer
Feb 25, 2018

4/25

Explanation:

First, we have the probability of drawing a green marble as 6 out of (6+9), which is 6/15.

After that, we replace the green marble into the bag. At this moment, the bag becomes the same as it is before a green marble is drawn, i.e. there are still 6 green marbles and 9 red ones.
If we are too draw another green marble, the same probability, 6/15, will be resulted.

As both requirements have to be fulfilled, the required probability is the multiplication of both,
=6/15*6/15

=36/225

=4/25