Imagine a large cube made up from $27$ small red cubes.
Imagine dipping the large cube into a pot of yellow paint so the
whole outer surface is covered, and then breaking the cube up into
its small cubes.
This text is usually replaced by the Flash movie.
How many of the small cubes will have
yellow paint on their faces?
Will they all look the same?
Now imagine doing the same with other cubes made up from small red
cubes.
What can you say about the number of small cubes with yellow paint
on?
Send us any interesting discoveries you make.
A poster of this problem is
available here.