math
posted by chrisopher on .
a cube is painted blue,then cut into 27 smaller cubes.how many of the smaller cubes have only two side painted/ggggggggggg

the cut cube must be 3 by 3 by 3
the only cubes that are painted on 2 sides would be the middle cubes along each edge.
There would be 12 of those.
(make a sketch to see the different cases)
none visible : 1
one visible : 6
two visible : 12
three visible : 8
total = 27