A person allows a 10% discount for cash payment from the marked price of a toy and still he makes a 10% gain. What is the cost price of the toy which is marked Rs. 770?
Answer & explanation
Answer: (c) Rs. 630
After a 10% discount the toy sells for Rs. 693. That price already includes a 10% gain, so the cost price is 693 ÷ 1.1 = Rs. 630.
- Selling price = 90% of Rs. 770 = Rs. 693.
- Cost price × 1.1 = 693, so cost price = Rs. 630.
- Check: 630 × 1.1 = 693.
Remember · Chain the percentages: marked price × (1 − discount) = cost price × (1 + gain).
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). ·