math question

Test Preparation SAT Preparation
1

<p>A large solid cube is assembled by gluing together identical unpainted small cubic blocks. All six faces of the large cube are then painted red. If exactly 27 of the small cubic blocks that make up the large cube have no red paint on them, how many small cubic blocks make up the large cube.</p>

<p>the correct answer is 125 i just don't know how to solve the problem.</p>

2

<p>Imagine the 27 unpainted cubes arranged to form a cube, 3 by 3 by 3.
Next, add cubes to enclose the unpainted core. When you are done, you will find you have a bigger cube, 5 by 5 by 5, for total count 125.</p>

3

<p>thanks for the help</p>