The diagram shows a driveway to be paved. The Lincoln family needs to determine the amount of Hot Asphalt Mix to purchase in order to pave their new driveway, which will have a 6-inch base (thickness). The density of Hot Asphalt Mix depends on mix proportions and types of material used. Assuming a density of 145 pounds per cubic foot, how many tons of asphalt will the Lincoln family need to purchase?