Three cards are drawn without replacement from the 20 cards that make up the 4s, 5s, 6s, 7s, and 8s from an ordinary deck of 52 playing cards. Let X be the number of 7s selected and the number of 6s. (a) Find the joint probability distribution of X and Y. (b) Find PIX.Y)EA], where A is the region given by {(x,y) [x+y21). (a) Complete the joint probability distribution below. (Type integers or simplified fractions.) f(x,y) o 2 0 1 2 3 (b) P[(XY)EA)-(Type an integer or simplified fraction.)