One urn contains two black balls (labeled B1 and B2) and one white ball. A second urn contains one black ball and two white balls (labeled W1 and W2). Suppose the following experiment is performed: One of the two urns is chosen at random. Next a ball is randomly chosen from the urn. Then a second ball is chosen at random from the same urn without replacing the first ball.
a. Construct the possibility tree showing all possible outcomes of this experiment.
b. What is the total number of outcomes of this experiment?
c. What is the probability that two black balls are chosen?
d. What is the probability that two balls of opposite color are chosen?