there are two urns..U1 and U2... In U1 there are three white balls and two red balls. In urn U2 there is only one white ball. now a coin is tossed.if head appears..then only one ball is taken out of U1 randomly and put into U2. if tail appears..then 2 balls are taken out of U1 and put into U2 randomly.
now after doing this...a ball is randomly chosen from U1..what is the probability that the ball is white???