You want to put a 6-inch thick layer of topsoil for a new 31 feet by 34 feet garden.

Question

The dirt store only sells topsoil by the cubic yard. How many cubic yards of topsoil will you need to order to fill this garden?

Answer 1

31(34)(1/2) = 31(17) = 527 cubic feet

1 cubic yard = 3^3 = 27 cubic feet

527/27 = about 19.52 cubic yards

You need to purchase 20 cubic yards to fill the garden

20 yd^3 = 20x3^3 = 20x27 = 540 ft^3

you'll have 540-527 = 13 ft^3 extra