A plumber charges a call-out fee plus an hourly rate. The total charge, C pounds, for a job lasting h hours is modelled by C = 35h + 60.
(a)Write down the call-out fee (the fixed charge before any hours are worked).(1)
(b)Write down the hourly rate charged.(1)
(c)Calculate the total charge for a job lasting 3.5 hours.(2)
(d)A customer is charged 235 pounds for a job. Work out how many hours the job lasted.(2)
(e)A second plumber charges according to the sequence of costs for whole numbers of hours: 90, 120, 150, 180, ... (for h = 1, 2, 3, 4 hours). By finding the nth term of this sequence, write down an equation for the second plumber's charge, C pounds, in terms of h hours, and state which plumber is cheaper for a 6-hour job.(4)