Question

Two urns each contain green balls and blue balls. Urn I contains 4 green balls and 6 blue balls, and Urn II contains 6 green balls and 2 blue balls. A ball is drawn at random from each urn. What is the probability that both balls are blue?

Answer 1

easy way to do this is use a probability tree diagram

urn 1 contains 10 balls, urn 2 contains 8 balls




the probability of B B is found by multiplying the probabilities of B B shown on the tree.

hope this helps.