Two Statements are given followed by two Conclusions:
- Statements: All cats are dogs. All cats are black.
- Conclusion-I: All dogs are black.
- Conclusion-II: Some dogs are not black.
Which of the above Conclusions logically follows/follow from the two given Statements, disregarding commonly known facts?
Answer & explanation
Answer: (c) Neither Conclusion-I nor Conclusion-II
The statements only tell us that every cat is both a dog and black, so some dogs are black. The other dogs may be black or not: 'all dogs are black' and 'some dogs are not black' are each possible, but neither is forced, so neither follows.
- Cats lie inside both 'dogs' and 'black', so some dogs (the cats) are black.
- Diagram 1: dogs outside the cats circle are not black — then Conclusion-I fails.
- Diagram 2: all dogs lie inside 'black' — then Conclusion-II fails.
- Each conclusion fails in some valid diagram, so neither follows. (Exactly one of them is true in any given case, but the statements do not tell us which.)
Remember · Draw one diagram where a conclusion fails; if you can, it does not follow. Contradictory conclusions can both fail to follow.
Question and answer: UPSC's official GS Paper II (2020, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). ·