4.3.3 Suppose that in Problem 4.3.2 we return the second ball to the urn, and add new balls as described, with the condition that if the second ball is blue, we add one ball of each color. Then we draw the third ball. What is the probability that the third ball is: (i) Blue. (ii) Blue if the first ball was red. (iii) Blue if the second ball was red. (iv) Blue if no blue ball was drawn on any of the preceding draws?