Toffees for a rupee — Profit & Loss Aptitude Question
Toffees for a rupee: A vendor buys toffees at 6 for a rupee. How many must he sell for a rupee to gain 20%? Answer and worked solution on CodeKairo.
- Topic: Profit & Loss
- Section: Quantitative Aptitude
- Difficulty: Medium
- Time target: 90 seconds
Question
A vendor buys toffees at 6 for a rupee. How many must he sell for a rupee to gain 20%?
Options
- 3
- 4
- 5
- 6
Show the answer and the worked solution
Correct answer: C. 5
Worked solution
- CP of one toffee = ₹1/6.
- For a 20% gain, SP of one toffee = (1/6) × 1.2 = ₹0.20.
- At ₹0.20 each, one rupee buys 5 toffees.
Answer: 5.
The idea
Work in price per unit, then invert at the end. Note the inverse relation: to gain, you must sell fewer per rupee, so the answer is always below the buying count.
Shortcut. The count per rupee varies inversely with price: raising the price by 6/5 divides the count by 6/5, and 6 × 5/6 = 5.
Common trap. 4 — knocking 20% off the 6 toffees gives 4.8, and rounding down to a whole toffee gives 4; the count must be 6 ÷ 1.2, not 6 × 0.8.