A statue company uses one roll of wrapping paper to wrap forty 4 inch tall busts...

Question

A statue company uses one roll of wrapping paper to wrap forty 4 inch tall busts of Beethoven. How many rolls are needed to wrap 385 12 inch tall busts?  

 

The answer is, as a real world integer, 29 rolls, but I can't get it. I'm treating it as a scaling problem, but I'm not sure how to scale the V/Area/Length in this one. Please tell me how to get 29. Thanks!

Answer 1

We don't know the Volume and Surface Area of the busts and rolls of wrapping paper, so this problem may be best solved by using the lengths since they, along with the quantities, are the only numbers we are given to work with.

 

If one roll of wrapping paper wraps 40 4-inch tall busts, then one roll will wrap 40/3=13.333 12-inch tall busts, since the 12-inch bust is 3 times larger (in length) than the 4-inch bust. Now, we need to wrap 385 12-inch busts. Simply divide 385 by (40/3) to get 28.875, which is the number of rolls needed to wrap the 385 12-inch busts. Round 28.875 up to 29, so that we have an integer value for the number of rolls and so that we can be sure to have enough (plus some extra) to wrap the required items.