A building contractor is building a backyard playground and wishes to put down rubber mulch to provide safety from falls. The contractor wishes to put the mulch in a pit in the shape of a rectangular solid 27 feet long, 18 feet wide, and 6 inches deep.

a) Determine the volume, in cubic feet, of mulch the contractor will need.
b) If mulch costs $11 per cubic foot, what will the cost of mulch be?