Question

A construction crew is pouring concrete to make a floor in a building. The weight of the concrete is proportional to the volume of concrete that has been poured. After pouring 5 cubic feet, they know the weight of the concrete is 740 pounds. If the construction crew uses a total of 12 cubic feet of concrete, how much would the concrete weigh?

Answer 1

To find the weight of 12 cubic feet of concrete, a proportion based on the given weight of 5 cubic feet is set up and solved, resulting in a weight of 1776 pounds.

Step-by-step explanation:

Since the weight of concrete is proportional to its volume, we can set up a ratio using the given weight and volume. We know that 5 cubic feet of concrete weighs 740 pounds. To find the weight of 12 cubic feet of concrete, we use a proportion:

5 cubic feet / 740 pounds = 12 cubic feet / x pounds

By cross-multiplying and solving for x, we get:

5x = 740 * 12

x = (740 * 12) / 5

x = 1776 pounds

Therefore, 12 cubic feet of concrete would weigh 1776 pounds.