Bill's Barbershop has two barbers available to cut customers' hair. Both barbers provide roughly the same experience and skill, but one is just a little bit slower than the other. The process flow in Figure 7.7 shows that all customers go through steps B1 and B2 and then can be served at either of the two barbers at step B3. The process ends all customers at step B4. The numbers in parentheses indicate the minutes it takes that activity tp process a customers.

a. How long does it take the average customer to complete this process?

b. What single activity is the bottleneck for the entire process?

c. How many customers can this process serve in an hour?