Each day a large animal clinic schedules 10 horses to be tested for a common respiratory disease. The cost of each test is $80. The probability of a horse having the disease is 0.1. If the horse has the disease, treatment costs $500.
a). What is the probability that at least one horse will be diagnosed with the disease on a randomly selected day?
b). What is the expected daily revenue that the clinic earns from testing horses for the disease and treating those that are sick?