Question

When the owner of a gas station sets the price of 1 gallon of unleaded gasoline at 2$, he can seek approximately 20,000 gallons per day. When he sets the price of gas at 5$ per gallon, he can sell approximately 14,000 gallons per day. Let G(x) denote the number of gallons of unleaded gasoline per day when the price is x dollars. Assume that G(x) is a linear function of x. Approximately how many gallons will be sold per day if the price of gasoline is 2.50$ per gallon?