The owner of a grocery store finds that she sell 980 gallons of milk each week at $2.69 per gallon and 1220 gallons of milk each week at $2.49 per gallon.

a) Find a linear function G(p) that gives the number of gallons sold as a function of the price of the milk.

b) How many gallons would she then expect to sell at $2.99 per gallon?

c) According to your function; if the owner sold 800 gallons of milk, what was the price per gallon?