Question:
A cube of side 5 cm is painted on all its faces. If it is sliced into 1 cubic centimetre cubes, then how many 1 cubic centimetre cubes will
have exactly one of their faces painted?
(a) 27
(b) 42
(c) 54
(d) 142
Solution:
(c) Given, a cube of side $5 \mathrm{~cm}$ is painted on all its faces and is sliced into $1 \mathrm{~cm}^{3}$ cubes. Then, from figure, it is clear that
there are 9 cubes available on face.
Since, there are six faces available.
Hence, total number of smaller cubes $=6 \times 9=54$