A barber shop has one barber who can give 12 haircuts per hour. Customers arrive at a rate of 8 customers per hour. Customer inter-arrival times and service times are exponentially distributed. The following queuing analysis spreadsheet was developed from this information.

M/M/s queuing computations
	Arrival rate	8
	Service rate	12
	Number of servers	1	(max of 40)
Utilization			66.67%
P(0), probability that the system is empty			0.3333
Lq, expected queue length			1.3333
L, expected number in system			2.0000
Wq, expected time in queue			0.1667
W, expected total time in system			0.2500
Probability that a customer waits			0.6667

I. Refer to Exhibit 13.2. Based on this report what percent of the time is the barber busy cutting hair?

a. 66.67%

b. 33.33%

c. 0.6667

d. 0.3333