In order to prepare a piece of ground for building a brick patio, a rectangle measuring 8 feet by 10 feet must be marked off. Then the dirt within the

rectangle must be dug out to a depth of 6 inches. Finally, the resulting space must be filled with sand. (b) Sand costs $4 per cubic foot. What is the total cost of the sand needed to fill this space, including a $35 delivery charge? (a) What is the volume of sand needed, in cubic feet, to fill the space?