A printer uses ink such that the number of pages printed, P, and the volume of ink used, I ml, are in the ratio P:I = 40:3.
(a)Write I as a linear function of P, in the form I = kP.(1)
(b)Use your linear function to find the volume of ink used when 500 pages are printed.(2)
(Total for Question 19 is 3 marks)