In an examination, 80% of students passed in English, 70% of students passed in Hindi and 15% failed in both the subjects. What is the percentage of students who failed in only one subject?
Answer & explanation
Answer: (b) 20%
20% failed in English and 30% in Hindi, with 15% failing both. So 5% failed only English and 15% failed only Hindi: 20% failed in exactly one subject.
- Failed in English = 100 − 80 = 20%; failed in Hindi = 100 − 70 = 30%.
- Failed in both = 15%.
- Failed only in English = 20 − 15 = 5%; failed only in Hindi = 30 − 15 = 15%.
- Failed in only one subject = 5 + 15 = 20%.
- Check: passed in both = 100 − (20 + 30 − 15) = 65%, and 65 + 20 + 15 = 100.
Remember · Work with the failure sets: ‘only one’ = (A − both) + (B − both).
Question and answer: UPSC's official GS Paper II (2024, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). ·