[16 pts] Suppose the joint pmf of the discrete random variables X and Y is X 0 1 2 Y 0 0.1 0.2 2 0.3 0 0.1 3 0.1 0.2 0 (a) [3 pts] Find P(X = 1|Y = 3) (b) [3 pts] Find the mean of U = X - 2Y (c) [5 pts] Calculate the covariance of X and Y. (d) [5 pts] Find the variance of U = X - 2Y