1 Face has 0 face painted
Step-by-step explanation:
As per the question a painted cube that is cut into 27 equal-size smaller cubes has been cut into a 3 * 3 * 3 arrangement.
There is 1 cube in the very center
On each of the 6 sides of the cube, there is a central smaller cube that is painted once.
Of the 27 (3*3*3) smaller cubes formed by the cutting, 1 gets no paint, 6 are painted on 1 face, 12 are painted on 2 faces, and 8 are painted on 3 faces (total 27 cubes).
1 (no paint) + 6 (painted 1) + 12 (painted 2) + 8 (painted 3) = 27 total
The sum of the painted faces (of the small cubes) is 54 (which is 6*9).