# Thread: The plumber is a crook!

1. ## The plumber is a crook!

A plumber charges $93 for a job which takes 2 hours and$141 for 4 hours of work. Let $C be the plumbing cost for t hours of work. What is the linear rule connecting C and t? 2. Originally Posted by Joker37 A plumber charges$93 for a job which takes 2 hours and $141 for 4 hours of work. Let$C be the plumbing cost for t hours of work. What is the linear rule connecting C and t?
Use the model C = at + b where b is a fixed cost and a is the hourly rate.

Then:

93 = 2a + b .... (1)

141 = 4a + b .... (2)

Solve equations (1) and (2) for a and b.