2. A show is scheduled to start at 9:00 p.m., 9:30 p.m., and 10:00 p.m. Once the show starts, the gate will be closed. A visitor will arrive at the gate at a time uniformly distributed between 8:30 p.m. and 10:00 p.m. Determine the following: a. Mean and variance of the arrival time b. Probability that a visitor waits less than 10 minutes for a show c. Probability that a visitor waits more than 20 minutes for a show