Question

Kimiko works at the drive-thru window in a fast-food restaurant. At the end of a 2-hour shift, the display at her window shows that she took an average of 1 minute and 20 seconds to serve each customer. How many customers came through the drive-thru during those 2 hours?

Answer 1

90 customers

Explanation:

Total shift time = 2 hours

1 hours = 60 minutes

Total shift time minutes = 2*60 minutes = 120 minutes

Average Time taken to serve 1 customer = 1 minute 20 seconds

lets convert 1 minute 20 seconds in fraction

60 seconds = 1 minute

20 seconds = 20/60 minutes = 1/3 minutes

Thus,

Average Time taken to serve 1 customer = 1 minute + 1/3 minutes = 4/3 minutes

Lets assume she served x customer in her 2 hour shift

total time taken to serve x customer =x*Average Time taken to serve 1 customer = 4x/3 minutes

Given that she the customers for her shift time which is 120 minutes

4x/3 minutes = 120 minutes

x = 120*3/4 = 90

Thus,

Kimiko served 90 customers and this is the number of customer which came through the drive thru during those 2 hours.