Question

Sarah currently earns $18.00 an hour at her job. Thanks to her hard work, her boss is going to give her a 20% raise. How much will she earn each hour after the raise?

Answer 1

21.6 $ / h

Explanation:

Since it is a raise you'll calculate by multiplying the $ / h by (1 + % / 100)

In this case 1 + % / 100 = 1 + 20 / 100 = 1 + 0.20 = 1.20

1.20 * 18 = 21.6 $ / h

NB.:

If it was a decrease by 20 % => 1 - 20 / 100 = 1 - 0.20 = 0.80

You would multiply the $ by 0.80.