A और B स्टील के दो भारी खंड हैं । यदि B को A के शीर्ष पर रखा जाता है, तो वज़न 60% बढ़ जाता है । यदि B को A के शीर्ष से हटा दिया जाए, तो A और B के कुल वज़न की तुलना में कितना वज़न कम हो जाएगा ?
Read this question in English
A and B are two heavy steel blocks. If B is placed on the top of A, the weight increases by 60%. How much weight will reduce with respect to the total weight of A and B, if B is removed from the top of A?
(a) 60% · (b) 45.5% · (c) 40% · (d) 37.5%
उत्तर और व्याख्या · explanation in English
Answer: (d) 37·5%
B weighs 60% of A, but the fall is measured against the larger total A + B. Removing 60 from 160 is a 37.5% reduction, not 60%.
- Let A weigh 100. B on top raises the weight by 60%, so B = 60.
- Total weight of A and B = 160.
- Removing B takes away 60 out of 160.
- Reduction = 60/160 × 100% = 37.5%.
Remember · A rise of r% is undone by a fall of r/(100 + r) × 100% — divide by the new, larger base.
Question and answer: UPSC's official GS Paper II (2019, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). ·