Question

Two urns contain white balls and yellow balls. The first urn contains 9 white balls and 9 yellow balls and the second urn contains 8 white balls and 3 yellow balls. A ball is drawn at random from each urn. What is the probability that both balls are white?

Answer 1

add the total number of balls in both urns, white and yellow...this is your denominator. Then add just the white balls...this is your numerator...reduce if it reduces. I think that is how you do it