How many overtime hours did the plumber work? Write and solve an equation.

Question

A plumber charges $30 per hour and $42 for every hour overtime. For a job, he works 3 regular hours, h overtime hours, and charges $195 for new parts. The total amount is $390. 

Answer 1

Remember, if you multiply a rate by the time, you'll get the fee for that amount of time.

 

He worked 3 regular hours at $30 per hour, so he'll charge 3·30 or $90 for the regular work.

He worked h overtime hours at $42 per hours, so he'll charge h·42 or $42h for the overtime work.

 

The total fee of $390 is the sum of the regular hours, the overtime hours, and the cost of the parts, so we add those there amounts and set them equal to the total.

 

90+42h+195=390.

42h+285=390

42h=105

h=2.5

 

The plumber worked 2.5 hours of overtime.