Question

An electrician charges $15 per service call plus $25 an hour plus the cost of the parts used. The total bill for a recent job was $155. If the parts for the job cost $65, find the number of hours the electrician worked.

Answer 1

Let us assume that he worked for T hours. The cost of his service for T hours will be 75 T dollars. Again, there is a service call cost which is $ 30. So, the total cost would be equal to $ (30+ 75 T ) and this value must be equal to $210. The answer is 2.4 hours.