Question

a company makes concrete bricks shaped like rectangular prisms. each brick is 15 inches long, 10 inches wide, and 5 inches tall. if they used 15,000 in³ of concrete, how many bricks did they make?

Explanation:

Step1: Calculate volume of one brick

The volume $V$ of a rectangular - prism is given by $V = l\times w\times h$, where $l = 15$ inches, $w = 10$ inches and $h = 5$ inches. So $V=15\times10\times5=750$ $in^{3}$.

Step2: Calculate number of bricks

Let the number of bricks be $n$. We know the total volume of concrete used is $15000$ $in^{3}$. Using the formula $n=\frac{\text{Total volume}}{\text{Volume of one brick}}$, we have $n=\frac{15000}{750}=20$.

Answer:

20