Answer: 22.59 yd^3
Step-by-step explanation:
First the volume of a cuboid whose measurements are:
L = length, W = width and T = thiknes is:
V = L*W*T.
We want to calculate the volume of a shape that is:
10'' thick, 18' wide and 42' long.
This notation is:
(') = feet
('') = inches
The first step is to write our 3 numbers in the same units, then we can use that:
1 inch = 0.083 ft.
Then 10 inches are equal to:
10'' = 10*(0.083 ft) = 0.83 ft = 0.83'
Then the volume of concrete needed will be:
V = 0.83ft*18ft*42ft = 627.48 ft^3
But we want this expressed in yd^3
1ft = 0.33 yd
then
1ft^3 = (0.33 yd)^3 = 0.036 yd^3
then 627.48 ft^3 can be written as:
627.48 ft^3 = 627.48*( 0.036 yd^3) = 22.59 yd^3