Question

A plumber is laying pipe. His assistant digs a trench in roughly the shape of a rectangular solid measuring 150 ft. in length, 9 inches deep along both sides, and 12 inches wide at the top and bottom. How many cubic feet of earth did he remove (to the nearest tenth)?

cubic feet

Answer 1

112.49 cubic feet

Explanation:

We are given that a trench in roughly the shape of a rectangular solid measuring 150 ft. in length, 9 inches deep along both sides, and 12 inches wide at the top and bottom.

We are supposed to find How many cubic feet of earth did he remove (to the nearest tenth)

So, Volume of Trench = Volume of Earth removed

Trench is in shape of rectangular solid.

Length = 150 feet

Height = 9 inches =
`9 * 0.0833333`=0.7499997 feet

Width = 12 inches=
`12 * 0.0833333`=0.9999996 feet

Volume of trench =
`Length * width * height`

=
`150 * 0.7499997 * 0.9999996`

=
`112.49991`

Hence he removed 112.49 cubic feet of earth.

Answer 2

Volume of trench = Amount of earth removed
Volume of trench = length x width x height = 150 x 12/12 x 9/12 = 150 x 1 x 3/4 = 112.5 cubic feet

Therefore, he removed 112.5 cubic feet of earth.