A Grocery Store Has Two Identical Checkouts; Each Can Serve

Multiple Choice

A grocery store has two identical checkouts; each can serve an average of 20 customers per hour following an exponential distribution. Customers ready to check out arrive at a common checkout line following Poisson distribution with a rate of 30 per hour. The utilization of the system will be:

A) 1.5
B) 0.75
C) 0.667
D) 0.25