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2005 Alabama ARML TST Problems/Problem 2

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Problem

A large cube is painted green and then chopped up into 64 smaller congruent cubes. How many of the smaller cubes have at least one face painted green?

Solution

The cube is 4\times 4\times4. Only the inside sub-cubes are unpainted, thus 8 are unpainted, leaving 64-8=56 painted.

See also

2005 Alabama ARML TST (Problems)
Preceded by:
Problem 1
Followed by:
Problem 3
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Looking for a challenging geometry text? Preparing for MATHCOUNTS or the AMC exams? Check out Art of Problem Solving's Introduction to Geometry by Richard Rusczyk.
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