2. Ms. Browning has a box with 1 red marker, 1 blue marker, and 1 yellow marker in it. She will reach into the box without looking, select a marker, use it, and put it back. She will do this a second time. All of the possible combinations that Ms. Browning could select are shown in the tree diagram below. What is the probability that Ms. Browning will select a blue marker both times?
1/3
1/6
1/9
1/2​