It takes you 1 gallon of paint to paint the inside of a box. The next
day you paint a box that has the same ratios of length to width and
length to height, but it takes you 2 gallons to paint the box. You
conclude that the total inside area of the larger box is twice that of
the smaller box. You conclude that the volume of the larger box
equals
times that of the smaller box.
Hint: Understand
scaling.