Question

$125$ cubes of same size are arranged as given in the following figure. They are painted from outside.

How many cubes have four sides coloured?

• A. $0$
• B. $4$
• C. $8$
• D. $12$

Answer 1

Answer: (D)

$12$

At the top level, the corner cubes will have colour on their four sides. There are $8$ corners, so there will be $8$ cubes on top level which are painted on their four faces.

$4^{th}$ level(from top) has $4$ cubes which are coloured on $4$ faces.

Thus, the total no. of cubes having colour on $4$ faces $=8+4=12$.

Hence, option D is correct.