Tourists arrive at a security checkpoint at the rate of 25 per hour. The checkpoint has a single machine that scans all tourists wanting to enter the secure area. Tourists are scanned one at a time according to a first-come, first-served discipline. A constant 90 seconds are required to scan a tourist. Compute the following:
a. Percent of time the scanning machine is busy
b. Average number of tourists waiting in line to be scanned
c. Average time spent in the line waiting to be scanned
d. Average time spent in the system (waiting time and scanning time)
e. Average number of tourists in the system