Cathy earns $13.50 per hour for the first 40 hours worked in a week and 20.25 per hour for hours over 40. if she earns 661.50 one week, how many hours does she work?

Set up an equation to help you determine the amount of hours she works.

13.5(40) + 20.25x = 661.50

Multiple 13.5 and 40.

540 + 20.25x = 661.50

Subtract 540 from both sides to get x by itself.

20.25x = 121.5

Divide 20.25 off of both sides to get the amount of hours she worked after completing 40 hours. 

x = 6

Now add 40 and 6 together, which is 46.

She worked 46 hours in that week.