A Big City Automobile Quick Oil Change Store Can Process

Multiple Choice

A big city automobile quick oil change store can process 20 vehicles per hour over its multiple bays. Each mechanic can change the oil and do other related tasks at a rate of one car every 20 minutes. If the center wanted a target labor utilization of 90%, how many mechanics would they require?

A) More than 4 but less than or equal to 6
B) More than 6 but less than or equal to 8
C) More than 8 but less than or equal to 10
D) More than 10