What is the correct equation to find the total weight of a box containing 27 cubic feet of sand weighing 105 lbs per cubic foot and an empty weight of 1,200 lbs?

The rationale behind the choice of the equation involving multiplying the volume of the sand, 27 cubic feet, by its weight per cubic foot, 105 lbs, is based on the fundamental principle of calculating weight from volume and density. To accurately determine the total weight of the box, you first need to establish the weight contributed by the sand itself, which is done by performing the multiplication of the volume by the weight per cubic foot.

This gives you the total weight of the sand. Then, to find the overall total weight, you simply need to add the weight of the empty box, which is 1,200 lbs.

So, the calculation process is to first compute the weight of the sand, which is 27 cubic feet multiplied by 105 lbs per cubic foot. After finding that product, you add it to the empty weight of the box. This approach ensures that both the sand and the container’s weights are included in the final total, providing an accurate representation of the overall weight.

The other equations do not correctly reflect the method of calculating total weight, as they either confuse the arithmetic operations or the elements being summed, which would lead to incorrect results.