Answer:
72
Step-by-step explanation:
When the original cube is cut into smaller cubes, the cubes on the edges and corners will have different numbers of painted faces. The smaller cubes on the edges will have 4 painted faces, and there are 12 edges on the original cube, so there will be 12 * 4 = 48 such cubes. The smaller cubes on the corners will have 3 painted faces, and there are 8 corners on the original cube, so there will be 8 * 3 = 24 such cubes. Therefore, the total number of smaller cubes painted on exactly two surfaces is 48 + 24 = 72.
