RAS question
A cube has six faces painted with six different colours: Red, Blue, Green, Yellow, White, Black. Red is opposite to Green. Blue is adjacent to Red. White is opposite to Black. Which colour is opposite to Blue?
Correct answer: (B) Yellow.
In the given cube arrangement, Yellow is opposite to Blue.
Explanation
A cube has six faces, so its faces form three opposite pairs. The question already fixes two such pairs: Red is opposite to Green, and White is opposite to Black. Blue is also given as adjacent to Red, so it cannot be opposite to Red; in any case, Red's opposite face is already occupied by Green. Once the Red-Green pair and the White-Black pair are placed, only Blue and Yellow remain unpaired. Therefore, the remaining opposite pair must be Blue and Yellow. This is exactly the kind of shape-and-space reasoning NCERT links to recognising 3D shapes, their observable properties, and spatial relationships such as top, bottom, above and below.
Why the other options are wrong
- (A) White cannot be opposite to Blue because White is already fixed as the opposite face of Black.
- (C) Black cannot be opposite to Blue because Black is paired with White as an opposite face.
- (D) Green cannot be opposite to Blue because Green is already fixed as the opposite face of Red.
Concept
This tests cube-based spatial reasoning: use the six-face structure of a cube and eliminate already fixed opposite pairs. It fits Reasoning & Mental Ability because the answer depends on visualising adjacency and opposites, not on memorising a fact.