Consider X and Y two random variables of probability densities pl(x) and p202), respectively. The random variables X and Y are said to be independent if their joint density function is given by p(x, y) = pl(x)p2(y). At a drive-thru restaurant, customers spend, on average, 3 minutes placing their orders and an additional 5 minutes paying for and picking up their meals. Assume that placing the order and paying for/picking up the meal are two independent events X and Y. If the waiting times are modeled by the exponential probability densities 1 1 -1 e 3, x Z 0 e 5, 2 0 mm = 3 and p200 = 5 y 0, otherwise 0, otherwise respectively, the probability that a customer will spend less than N minutes in the drive-thru line is given by P(X+ Y5 N) =J] p(x,y)dA whereD = {(x,y)|x2 0,322 0,x+y 5N}. D Compute the probability that a customer will spend less than 6 minutes in the drive-thru