2 blue and 3 red marbles are in a bag. If you draw a marble from the bag and do not replace it, what is the probability of drawing 2 blue marbles?

In this diagram, you begin with two branches: drawing a blue marble and drawing a red marble . Remember that, in such probability problems, it is helpful to think of these outcomes as blue and not blue .

The branch that shows the probability of finding 2 blue marbles is highlighted in the diagram below.

The probability of drawing 2 blue marbles with replacement is . This is found by multiplying the probability of each event.