Residents of the town of Maple Grove who are connected to the municipal water supply are billed a fixed amount monthly plus a charge for each cubic foot of water used. In other words, the monthly bill is a linear function of the water used. A household using 1000 cubic feet was billed $40, while one using 1600 cubic feet was billed $55. (a) What is the charge per cubic foot?

(b) Write an equation for the total cost of a resident s water as a function of cubic feet of water used.

(c) How many cubic feet of water used would lead to a bill of $100?