Given: Wooden little cubes each with an edge of one inch are put together to form a solid cube with an edge of three inches. It is then painted red all over the outside. When the big cube is broken - up into the original little ones, Cubes which have no face painted Shortcut Trick If a cube has been painted red, blue, and black on pairs of opposite faces and divide it into X parts. 1) Total number of cubes = X3 2) Cubes that have three faces painted = 8 (Because there are only 8 corners in the cube) 3) Cubes which has only two faces painted = (X - 2) × No of Edges (12) 4) Cubes that have only one face painted = (X - 2)2 × 6 5) Cubes which have no face painted = (X - 2)3 The cubes will be without paint: ⇒ (X - 2)3 ⇒ (3 - 2)3 ⇒ (1)3 ⇒ 1