A 5×5×5 wooden cube was painted and then sawed into 1×1×1 cubes. How many 1×1×1 cubes have exactly two faces painted?
The 1 x 1 x 1 cubes that have exactly two faces painted will be the edge pieces that aren't corner pieces.
There are 3 of these on each edge.
How many edges does a cube have?
Multiply that number by three to get the answer.