Richard had his car repaired at a body shop. The parts cost $100.
The technician charged $52 per hour.
. His total bill was $308.
How many hours did the technician work on Richard's car?

The total cost is 308,
Then you have to subtract the cost of the car parts which is 100
That will give you $208

After that you have to divide 52 from 208, this will give you 4.
Therefore the technician worked on Richards car for 4 hours.