A ate grapes and pineapple; B ate grapes and oranges; C ate oranges, pineapple and apple; D ate grapes, apple and pineapple. After taking fruits, B and C fell sick.
In the light of the above facts, it can be said that the cause of sickness was:
Answer & explanation
Answer: (d) Oranges
Oranges are the only fruit eaten by both B and C, who fell sick, and neither A nor D, who stayed well, ate oranges. Every other fruit was eaten by at least one person who did not fall sick.
- Sick: B (grapes, oranges) and C (oranges, pineapple, apple). The only fruit common to both is oranges.
- Well: A (grapes, pineapple) and D (grapes, apple, pineapple) — neither ate oranges.
- Check: grapes, pineapple and apple were all eaten by someone who stayed well, so they cannot be the cause.
Remember · To find a common cause, take what all affected cases share and strike out anything the unaffected cases also had.
Question and answer: UPSC's official GS Paper II (2016, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). ·