Each of n packages is loaded independently onto either a red truck (with probability p) or onto a green truck (with probability 1 - p). let r be the total number of items selected for the red truck and let g be the total number of items selected for the green truck. (a) determine the pmf, expected value, and variance of the random variable r. (b) evaluate the probability that the first item to be loaded ends up being the only one on its truck. (c) evaluate the probability that at least one truck ends up with a total of exactly one package. (d) evaluate the expected value and the variance of the difference r - g. (e) assume that n : 2: 2. given that both of the first two packages to be loaded go onto the red truck, find the conditional expectation, variance, and pmf of the random variable r.