Rubik Madness

Discrete Mathematics Level 1

If you take a $3 \times 3 \times 3$ Rubik cube and break it up into the $3^3$ cubes, how many cubes would have stickers on exactly $2$ faces?

Bonus question: Can you generalize this for a $N \times N \times N$ Rubik cube?

9 26 3 27 8 12 6

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