Question

Some equal cubes are arranged in the form of a solid block as shown in the adjacent figure. All the visible surfaces of the block (except the bottom) are then painted.

How many cubes have one face painted ?

• A. 9
• B. 24
• C. 30
• D. 20

Answer 1

Answer: (C)

30

No. of cubes with 1 face painted on the right face = 8
No. of cubes with 1 face painted on the back face = 8
No. of cubes with 1 face painted on the front face = 6
No. of cubes with 1 face painted on the left face = 6
No. of cubes with 1 face painted on the top face = 2
Total number of cubes with only 1 face painted = 8 + 8 + 6 + 6 +2 = 30