An automobile emissions testing center has six inspectors and tests 50 vehicles per hour. Each inspector can inspect 12 vehicles per hour. How many inspectors would the center require to have a target utilization of 90 percent? Round your answer up to the next whole number.

a. Two

b. Three

c. Seven

d. Five

Option (d) is correct.

Explanation:

Target utilization = 90% = 0.9

Total number of vehicles tested in an hour or arrival rate = 50 vehicles per hour

Number of vehicles that an inspector can inspect in an hour or service rate = 12

Let n be the number of inspectors required.

Utilization = arrival rate : (number of servers * service rate)

0.9 = 50 : (n * 12)

Hence,

n = 50 : (0.9 * 12)

= 4.63

Hence we can round off number of inspectors required as 5.