धर्मार्थ दान में, किसी कक्षा में प्रत्येक विद्यार्थी उतने रुपये देता है जितनी उस कक्षा में विद्यार्थियों की संख्या है। केवल एक विद्यार्थी के 2 रुपये अतिरिक्त देने पर कुल रुपये 443 एकत्र हुए हैं। तो कक्षा में कितने विद्यार्थी हैं ?
Read this question in English
In aid of charity, every student in a class contributes as many rupees as the number of students in that class. With the additional contribution of Rs. 2 by one student only, the total collection is Rs. 443. Then how many students are there in the class?
(a) 12 · (b) 21 · (c) 43 · (d) 45
उत्तर और व्याख्या · explanation in English
Answer: (b) 21
If there are n students, each gives Rs. n, so the collection is n². With the extra Rs. 2 it is 443, so n² = 441 and n = 21.
- n students each give Rs. n: total = n².
- n² + 2 = 443, so n² = 441 and n = 21.
- Check: 21 × 21 = 441; 441 + 2 = 443.
Remember · 'As many rupees as the number of people' makes the total a perfect square — look for the square near the figure.
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). ·