Which one of the following statements is correct ?
- (a) Weight of Mohan is greatest
- (b) Weight of Sohan is greatest
- (c) Weight of Rohan is greatest
- (d) 'Whose weight is greatest' cannot be determined ✓ UPSC's answer
Why the answer is (d)
• Read the statements as: twice Sohan's weight is less than both Mohan's and Rohan's weights (S1), and twice Rohan's weight is greater than both Mohan's and Sohan's weights (S2).
• From S1 Sohan is lighter than both others, so he cannot be the heaviest.
• The order of Mohan and Rohan is not fixed: Mohan 100, Rohan 60, Sohan 20 satisfies both statements (40 is less than 60 and 100; 120 is more than 100 and 20), and so does Rohan 100, Mohan 60, Sohan 20.
• Either Mohan or Rohan can be the heaviest, so whose weight is greatest cannot be determined, option (d).
Why the other options are wrong
- (a) Weight of Mohan is greatest
- Mohan need not be the heaviest: Rohan 100, Mohan 60, Sohan 20 also satisfies both statements.
- (b) Weight of Sohan is greatest
- Sohan cannot be the heaviest, since twice his weight is less than each of the others.
- (c) Weight of Rohan is greatest
- Rohan need not be the heaviest: Mohan 100, Rohan 60, Sohan 20 also satisfies both statements.
Asked in the CSAT Paper II of the UPSC Civil Services Preliminary Examination 2019, held on 2 June 2019. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.