What is the difference in cost between the quoted total and the actual cost for 13.5 hours?

• A. 108.75
• B. 109.75
• C. 108.00
• D. 107.50

Answer: (A)

The main idea is to compare what was quoted with what the actual cost turns out to be for 13.5 hours, and take the difference between those two totals. To do this you calculate the actual total by applying the shop’s labor rate (and any overtime or extra charges) for 13.5 hours. Then you subtract the quoted total from that actual total and take the absolute value. The result is the difference in cost.

In this problem the difference is 108.75, meaning the actual cost and the quoted total differ by 108.75. If you want a quick sense of the size, you can divide 108.75 by 13.5 to get about 8.06, which represents the average per-hour discrepancy contributing to that total difference. The essential point is that the correct choice reflects the magnitude of how far apart the two totals are for 13.5 hours.