(Solution Download) If the ball drawn from urn 2 is white what

If the ball drawn from urn 2 is white, what is the probability that the ball drawn from urn 1 was white?
In Problem, urn 1 contains 7 red and 3 white balls. Urn 2 contains 4 red and 5 white balls. A ball is drawn from urn 1 and placed in urn 2. Then a ball is drawn from urn 2.