Example Question #1 : Volume
The graphic below shows a blueprint for a swimming pool.
If the pool is going to be 66 inches deep, how many cubic feet of water will it be able to hold? (1 ft = 12 in)
Notice that the outer dimensions of the blueprint are the dimensions for the entire pool, including the concrete, while the inner dimensions are for the part of the pool that will be filled with water. Therefore, we want to focus on just the inner dimensions.
Notice that the depth is given in inches, while the dimensions are in feet. Convert 66 inches to feet by dividing 66 by 12, since 12 inches makes a foot:
The inch units cancel out and leave us with just the feet units. 66 in is 5.5 ft.
Now we have all of the information we need to solve for the volume of the pool. The pool is a rectangular prism, and the formula for volume of a rectangular prism is
(In this case, the "height" of the swimming pool is its depth.)
The blueprint shows that the pool is 40 ft long and 30 ft wide. Plugging in the measurements from the problem, we get
Multiplying this out, we get .