Problema Solution

two plumbers make house calls. one charges $120 for a visit plus $45 per hour of work. The other charges $90 for a visit and $55 per hour of work. For how many hours of work do the two plumbers charge the same?

Answer provided by our tutors

Cost equation for first plumber for 'x' hours:

C = 45x + 120

Cost equation for second plumber for 'x' hours:

C = 55x + 90


If the costs are the same, then:

45x + 120 = 55x + 90

10x = 30

x = 3


For three hours of work the two plumbers would charge the same.