Question

How many cubes have atleast two faces painted ?

• A. $36$
• B. $34$
• C. $28$
• D. $24$

Answer 1

Answer: (C)

$28$

In the given statement, there are $36$ cubes, $32$ of which are of the same size and $4$ other sure of bigger size. Clearly, each side of bigger cubes is twice as large as that of similar cubes. Also, since no face of any of the larger cubes is painted blue, so each one of the larger cubes has one face painted red, one is black and all other faces are unpainted.
There are no cubes having more than three faces painted. $8$ cubes at the edges of the block have three faces painted and as calculated above, $20$ cubes have two faces painted.

Thus, $8+20=28$ cubes have two or more faces painted.