Question

you are a concrete contractor who is developing a formula to determine the number of yards (y) of concrete needed for a foundation wall which is in the shape of a rectangular prism. let l be length in feet of the wall, w be width in feet of the wall, and h be height in feet of the wall. a yard of concrete is equal to 27 cubic feet of concrete. which of the following is a correct formula for the number of yards of concrete?
a. y = 27lwh
b. y = \frac{lwh}{27}
c. y = \frac{l + w + h}{27}
d. y = \frac{27}{lwh}
e. y = \frac{27}{l + w + h}

Explanation:

Step1: Calculate volume of the wall

The volume $V$ of a rectangular prism (the foundation wall) is given by the formula $V = L\times W\times H$ (where $L$ is length, $W$ is width and $H$ is height). The volume is in cubic - feet.

Step2: Convert cubic - feet to yards of concrete

Since 1 yard of concrete is equal to 27 cubic feet, to find the number of yards $Y$ of concrete, we divide the volume in cubic feet by 27. So $Y=\frac{LWH}{27}$.

Answer:

B. $Y = \frac{LWH}{27}$