2 Consider a random experiment of flipping a fair coin 3 times Let X be the number of tails in the first flip and Y the total number of tails in 3 tosses a What are possible values of X and Y b Express the event X a Y b a 0 1 and b 0 1 2 3 in terms of H and T of three tosses c Find the joint density px y a b of X and Y where a 0 1 and b 0 1 2 3