Question

How many cubes have two sides coloured?

• A. $4$
• B. $8$
• C. $12$
• D. $24$

Answer 1

The correct option is C $12$

At the last bottom level, $8$ cubes (after excluding the corner cubes) will have two faces colored. The corner cubes will have $3$ faces colored and the internal cubes will have $1$ face colored.

At the second-last bottom level, total $4$ cubes at each corner have color on two sides. Other cubes will have either $1$ face colored.

And no other levels have cubes with color on two faces.

Hence, the answer is $8+4=12$.