Three hairstylists, Franois, Bernard, and Mimi, run Fast Service Hair Salon for busy professionals in the Gold

Three hairstylists, François, Bernard, and Mimi, run Fast Service Hair Salon for busy professionals in the Gold Coast area of downtown Chicago (see Figure 5.1). They stay open from 6: 45 a. m. to 9: 00 p. m. in order to accommodate as many people’s work schedules as possible. They perform only shampooing and hairstyling activities. On average, it takes 10 minutes to shampoo, 15 minutes to style the hair, and 5 minutes to bill the customer. When a customer arrives, he or she first checks in with the receptionist (Bernard’s younger sister LuLu). This takes only 3 minutes. One of the three stylists then takes charge of the customer and performs all three activities— shampooing, styling, and billing— consecutively.
a. What is the number of customers that can be serviced per hour in this hair salon?
b. A customer of Fast Service Hair Salon, an operations specialist, has suggested that the billing operation be transferred to LuLu. What would be the impact on the theoretical capacity?