Jerry and Jill are playing in a bowling tournament. Their scores vary as they play

multiple games. Jerry's scores, X, follow a ( = 205, = 9) distribution. Jill's scores, Y, vary from game to game according to a ( = 200, = 7) distribution. Define a new random variable = - .

a) Assuming Jerry and Jill play independently, what is the distribution of D?

b) What is the probability that Jerry will score higher than Jill and thus do better in the tournament?