This question was found on page 57 of the Manhattan GMAT Formulas & Strategy Booklet
If the length of the side of a cube decreases by two thirds, by what percentage will the volume of the cube decrease?
So I was reviewing this question and the explanation seemed wrong to me.
Here's what they said: Plug in a number for a side and chose 9. The volume would be 9x9x9 = 729
Since the length of the side of a cube decreases by two thirds, its new length is now 3 units.
It's new volume is 3 x 3 x 3 = 27
So change/original = (729-27)/729 = 96.3%
The problem never said the length of every side decreased. It said the length of THE SIDE of a cube decreased which means one side to me.
Change/Original = (729 - 297)/729 =59.3% decrease
Any thoughts or explanations as to why we're supposed to assume that all sides of the cube are to shrink by two thirds if this wasn't specified????