Answer:
20 cubic yards
Explanation:
You want to know the volume in cubic yards of a layer of topsoil that is 6 inches deep over an area 31 feet by 34 feet.
Units
You know that ...
- 36 inches = 1 yard
- 3 feet = 1 yard
Then the dimensions of the volume being applied are ...
6 inches = 6/36 yards
31 feet = 31/3 yards
34 feet = 34/3 yards
Volume
The volume is the product of the dimensions of the space:
V = LWH
V = (31/3 yd)(34/3 yd)(6/36 yd) ≈ 19.519 yd³
About 20 cubic yards are needed to fill the garden.