Three Statements followed by three Conclusions are given below. You have to take the Statements to be true even if they seem to be at variance from the commonly known facts. Read all the Conclusions and then decide which of the given Conclusions logically follows/follow from the Statements, disregarding the commonly known facts:
- Statement–1: Some doctors are teachers.
- Statement–2: All teachers are engineers.
- Statement–3: All engineers are scientists.
- Conclusion–I: Some scientists are doctors.
- Conclusion–II: All engineers are doctors.
- Conclusion–III: Some engineers are doctors.
Which one of the following is correct?
Answer & explanation
Answer: (c) Both Conclusion–I and Conclusion–III
The doctors who are teachers are, by the chain of ‘all’ statements, also engineers and scientists. So “some engineers are doctors” and “some scientists are doctors” both follow; “all engineers are doctors” does not.
- Some doctors are teachers, and all teachers are engineers, so those doctors are engineers: some engineers are doctors (III follows).
- All engineers are scientists, so the same doctors are scientists: some scientists are doctors (I follows).
- Nothing says every engineer is a doctor, so II does not follow.
- ✓ I The doctor-teachers are engineers and hence scientists, so some scientists are doctors.
- ✗ II Only some engineers (those who are teacher-doctors) are known to be doctors; ‘all’ goes beyond the statements.
- ✓ III The doctors who are teachers are engineers, so some engineers are doctors.
Remember · A ‘some’ link passes down a chain of ‘all’ links: some A are B and all B are C, so some A are C.
Question and answer: UPSC's official GS Paper II (2022, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). ·