Marked up, then discounted — Percentages Aptitude Question
Marked up, then discounted: A shopkeeper raises the price of an article by 30% and then offers a 10% discount. Answer and worked solution on CodeKairo.
- Topic: Percentages
- Section: Quantitative Aptitude
- Difficulty: Easy
- Time target: 45 seconds
Question
A shopkeeper raises the price of an article by 30% and then offers a 10% discount. What is the net change in price?
Options
- 15% increase
- 17% increase
- 20% increase
- 22% increase
Show the answer and the worked solution
Correct answer: B. 17% increase
Worked solution
- Net factor = 1.30 × 0.90 = 1.17.
- That is a 17% increase.
Answer: 17% increase.
The idea
Never add or subtract successive percentages directly. Convert each to a multiplier and multiply; the answer is always slightly off the naive sum.
Shortcut. The 10% discount also removes 10% of the 30% mark-up, i.e. 3 points: 30 − 10 − 3 = 17% increase.
Common trap. "20% increase" — subtracting 10 from 30 directly, as though the discount were taken on the original price.