A drive thru car wash can process cars at a rate of one every five minutes. When you arrive with your car, you see one car just leaving the washer and eight cars in line ahead of you. How long can you expect to wait before you will reach the car wash?

Question

Quizplus · Accepted Answer

The number of cars ahead of you is eight, meaning that you are the ninth car in line. The car wash processes one car every five minutes, therefore, it will take the car wash 5 x 8 = 40 minutes to reach your car. Since the question is asking for an estimate, we can round up to the nearest multiple of 15, which would be 45 minutes. Therefore, the correct answer is C: greater than 30 but less than or equal to 45 minutes.

A Drive Thru Car Wash Can Process Cars at a Rate