A wood maker constructed a rectangular sandbox with a capacity of 10 cubic feet.

A wood maker constructed a rectangular sandbox with a capacity of 10 cubic feet. If the carpenter were to make a similar sandbox twice as long, twice as wide, and twice as high as the first sandbox, what would be the capacity, in cubic feet, of the second sandbox?

Quiz

Answer/Solution

80

Steps/Work

A quick note on doubling. When you double a length you have 2*L1. When you double all lengths of a rectangle you have (2*L1)(2*L2) = A. An increase of 2^2 or 4. When you double all lengths of a rectangular prism you have (2*L1)(2*L2)(2*L3) = V. An increase of 2^3 or 8.
This leads to the basic relationship:
Line: 2*original size
Rectangle: 4*original size
Rectangular Prism: 8*original size answer is D