A cube is painted green on all the sides. it is then cut into 64 cubes of equal size. how many of smaller cubes are painted on 1 side?

Cube root of 64 is 4 therefore cube is 4 x 4 x 4. Each side of the cube has 16 visible small cube faces, 4 of which are corners (3 green sides) and 8 more are edges (2 green sides), so there are only four small cubes with one green face on each of the six sides of the large cube. Your answer is therefore 24.