An instructor has given a short quiz consisting of two parts. for a randomly selected student, let x = the number of points earned on the first part and y = the number of points earned on the second part. suppose that the joint pmf of x and y is given in the accompanying table. y p(x, y) 0 5 10 15 x 0 0.02 0.06 0.02 0.10 5 0.04 0.13 0.20 0.10 10 0.01 0.15 0.16 0.01 (a) if the score recorded in the grade book is the total number of points earned on the two parts, what is the expected recorded score e(x + y)? (enter your answer to one decimal place.) (b) if the maximum of the two scores is recorded, what is the expected recorded score? (enter your answer to two decimal places.)