UPSC CSE Prelims 2013
What possible numbers can exist on the two faces marked (A) and (B), respectively on the cube?
The numbers 2 and 3 can exist on faces (A) and (B), respectively.
Based on the initial three views of the cube, the opposite faces can be determined through logical deduction:
Thus, the established pairs of opposite faces are: (1, 6), (2, 5), and (3, 4).
In the target view, the visible faces are 6, (A), and (B). A fundamental principle of a standard cube is that opposite faces cannot be simultaneously visible in any single perspective.
Option 2 (6 and 1): This option is incorrect. Firstly, the number 6 is already visible on one face of the cube; therefore, face (A) cannot also be 6. Secondly, 6 and 1 are opposite faces, and opposite faces cannot be simultaneously visible on a single view of the cube.
Option 3 (1 and 4): This option is incorrect because 6 and 1 are opposite faces. Since 6 is already visible in the given view, its opposite face, 1, cannot be visible on face (A).
Option 4 (3 and 1): This option is incorrect because 6 and 1 are opposite faces. Since 6 is already visible in the given view, its opposite face, 1, cannot be visible on face (B).