Loss equal to the cost of five balls — Aptitude Question
Loss equal to the cost of five balls: On selling 17 balls for ₹720, there is a loss equal to the cost price of 5… Answer and worked solution on CodeKairo.
- Topic: Profit & Loss
- Section: Quantitative Aptitude
- Difficulty: Medium
- Time target: 75 seconds
Question
On selling 17 balls for ₹720, there is a loss equal to the cost price of 5 balls. What is the cost price of one ball?
Options
- ₹45
- ₹50
- ₹55
- ₹60
Show the answer and the worked solution
Correct answer: D. ₹60
Worked solution
- Let the cost of one ball be ₹c.
- Loss = 17c − 720, and this equals 5c.
- 17c − 720 = 5c → 12c = 720 → c = ₹60.
Answer: ₹60.
The idea
Write loss as cost minus revenue, then equate it to the quantity the question describes. One linear equation settles it.
Shortcut. Losing the cost of 5 balls means ₹720 recovers the cost of 17 − 5 = 12 balls, so one ball costs 720 ÷ 12 = ₹60.
Common trap. "₹55" — valuing the loss at the selling price of 5 balls (5 × 720/17 ≈ ₹212) instead of their cost, which gives 17c ≈ 932 and c ≈ ₹55.