A solid wooden cube is painted blue on the outside. The cube is then cut into 27 smaller cubes

of equal size. What fraction of the total surface area of these new cubes is blue?

1 answer

let's say that the cube has an edge length of 3 units

so the blue surface area is
... 6 * 3^2

each of the smaller cubes has an edge length of 1 unit

so their collective surface area is
... 27 * 6 * 1^2