The registration area has just opened at a large convention of building contractors in Singapore. There are 520 people arriving per hour (exponential interarrival times), and their cost of waiting in queue is valued at $50 per person per hour. The Singapore Convention Bureau provides servers to register guests. The cost (salary) of a server is 40 dollars per hour. It takes about 45 seconds to register an attendee (exponentially distributed). A single waiting line with multiple servers is set up.

a) What is the minimum number of servers for this system?

b) What is the optimal number of servers for this system from a cost perspective?

c) What is the cost for the system, per hour, with the optimum number of servers?

d) What is the server utilization rate with the minimum number of servers?