Question

You are asked to buy bags of cement to pour a cement pad for a hot tub. you need to fill the pad frame which is a square frame measuring 8 feet long and 1 foot high. each bag of cement mixed will fill 5 cubic feet in the frame. how many bags will you need to buy to ensure enough to fill the entire frame

Answer 1

The volume of a rectangular prism (which the frame is, having a square base with height) is given by $V=lwh$, where l is length, w is width, and h is height. Since the width of a square is equivalent to its length, the square's dimensions will be 8 feet by 8 feet. So the volume of the frame is $V=8ft*8ft*1ft=64ft^{3}$.
We need to know how many $5ft^{3}$ bags fit in a $64ft^{3}$ frame, so we can divide 64 by 5 to find how many times 5 fits in 64: $\frac{64}{5}=12.8$. You can't buy 8 tenths of a bag, so you'll need to buy 13 bags to ensure that you have enough cement to fill the entire frame.