A plumber charges a fixed call-out fee plus a fixed hourly rate for the time spent on a job.
A job lasting 2 hours costs £115.
A job lasting 5 hours costs £250.
The plumber's charge, £CCC, for a job lasting t t\,t hours is modelled by a straight line.
Find an equation for C C\,C in terms of ttt.
Interpret the gradient and the vertical intercept of your model in the context of the question.
76 exam-style questions on WJEC A Level Maths 1.3 Coordinate geometry in the (x, y) plane, covering 1.3.1 Coordinate geometry in the (x, y) plane, 1.3.2 Coordinate geometry in the (x, y) plane, 1.3.3 Coordinate geometry in the (x, y) plane, and 1.3.4 Coordinate geometry in the (x, y) plane. Each one has a worked solution and a mark scheme showing where the marks go.