Doug earn $10.50 per hour working at a restaurant. on friday, he spent 1 3/4 hours cleaning, 2 1/3 hours doing paperwork, and 1 5/12 hours serving customers. what were doug's earning?

First, add all of the working hours.
1 3/4 + 2 1/3 + 1 5/12
Since the denominators are different, make them on all the same.
1 9/12 + 2 4/12 + 1 5/12
Add everything up.
4 1/12 + 1 5/12
5 6/12
Simplify.
5 1/2 or 5.5
Multiply the time by the salary.
5.5*10.5=57.75

Doug earned 57.75$