A cube with a side of 3 inches is painted green and then sliced into smaller cubes with 1 inch sides. How many of the

[M7MBA]

A cube with a side of 3 inches is painted green and then sliced into smaller cubes with 1-inch sides. How many of the smaller cubes have exactly three painted sides?

A) 4
b) 6
C) 8
D) 10
E) 12

Answer: C

Source: Economist

[Scott@TargetTestPrep]

A cube with a side of 3 inches is painted green and then sliced into smaller cubes with 1-inch sides. How many of the smaller cubes have exactly three painted sides?

A) 4
b) 6
C) 8
D) 10
E) 12

Answer: C

Solution:

The only smaller cubes that have exactly 3 painted sides (or faces) are those that were originally at each corner of the original bigger cube. Since a cube has 8 corners, there are 8 smaller cubes that have exactly 3 painted sides (or faces).

Answer: C