Question

please solve the 3 one.

Answer 1

First check yourself how many cubes are visible with no of faces it helps

★ all the corner cubes are exposed with three faces, do the 3 faces are painted

>>>>> 3 faces painted ------ 8 cubes

★ all the cubes along edges except corners are exposed with 2 faces

>>>>> 2 faces painted ------ 12 edges * 2 cubes = 24 cubes

★ all cubes in faces except the above discussed are exposed with a single face

>>>>> 1 face painted ------ 6 faces * 4 cubes on each = 24 cubes

★ rest of the cubes are non painted --- = total - 8 - 24 - 24

= 64 - 8 - 24 - 24 = 8 cubes

Hope you understand

If you have any doubts comment ;)(