90 प्रश्न वाली एक वस्तुनिष्ठ परीक्षा में, प्रत्येक सही उत्तर के लिए 5 अंक निर्धारित किए गए हैं और प्रत्येक ग़लत उत्तर के लिए 2 अंक घटाए जाते हैं । सभी 90 प्रश्नों का उत्तर देने पर, एक विद्यार्थी को कुल 387 अंक प्राप्त हुए । ग़लत उत्तरों की संख्या कितनी है ?
Read this question in English
In an objective type test of 90 questions, 5 marks are allotted for every correct answer and 2 marks are deducted for every wrong answer. After attempting all the 90 questions, a student got a total of 387 marks. What is the number of incorrect responses?
(a) 9 · (b) 13 · (c) 27 · (d) 43
उत्तर और व्याख्या · explanation in English
Answer: (a) 9
Full marks would be 90 × 5 = 450, and each wrong answer costs 5 + 2 = 7 marks compared with a right one. The shortfall of 63 marks means 9 wrong answers.
- If all 90 were correct: 90 × 5 = 450 marks.
- Each wrong answer loses 5 + 2 = 7 marks compared with a correct one.
- Shortfall = 450 − 387 = 63, so wrong answers = 63 ÷ 7 = 9.
- Check: 81 × 5 − 9 × 2 = 405 − 18 = 387.
Remember · Start from full marks and divide the shortfall by (marks for a correct answer + penalty for a wrong one).
Question and answer: UPSC's official GS Paper II (2021, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). ·