Question

Ron has a bag containing 3 green pears and 4 red pears. He randomly selects a pear then randomly selects another pear, without replacement. Which tree diagram shows the correct probabilities for this situation?

Answer 1

The third tree diagram is correct.

The probabilities for the first draw are 3/7 for green and 4/7 for red.

If you draw a green pear first, then your probabilities for the second pear would be 2/6 for green and 4/6 for red (since it is done without replacement, the number of pears to choose from changes).

If you draw a red pear first, then your probabilities for the second pear would be 3/6 for green and 3/6 for red.