Problem 9 a) An urn contains four red balls and four blue balls. You draw two balls from the urn, one after the other, without putting them back. Event A is that the first ball is red, and event B is that the second ball is red. Are events A and B independent? Prove your answer. b) This time you are using the same urn and balls, but you draw three balls, again one after the other. Event C is that the first two balls you draw have the same color, and Event D is that the third ball is red. Are events C and D independent? Again, prove your