To prepare a piece of ground for building a brick patio, a rectangle measuring 10 feet by 12 feet must be marked off. Then the dirt within the rectangle must be dug out to a depth of 2 feet. Finally, the resulting space must be filled with sand.

(a) What is the formula for volume? What is the volume of sand needed, in cubic feet, to fill the space?
Show your work!

Answer: ____________________ cubic feet

If you used your calculator, show the numbers and operations that you used to get your answer.

(b) What is the formula for volume? Sand costs $5 per cubic foot. What is the total cost of the sand needed to fill this space, including a $40 delivery charge?
Show your work!

Answer: $____________________

If you used your calculator, show the numbers and operations that you used to get your answer.