Two years of population growth — Aptitude Question
Two years of population growth: A town's population is 50,000 and grows by 10% every year. What will it be after 2… Answer and worked solution on CodeKairo.
- Topic: Percentages
- Section: Quantitative Aptitude
- Difficulty: Easy
- Time target: 45 seconds
Question
A town's population is 50,000 and grows by 10% every year. What will it be after 2 years?
Options
- 60,000
- 60,500
- 61,000
- 62,500
Show the answer and the worked solution
Correct answer: B. 60,500
Worked solution
- After year 1: 50,000 × 1.1 = 55,000.
- After year 2: 55,000 × 1.1 = 60,500.
Answer: 60,500.
The idea
Repeated percentage growth is compound growth: multiply by (1 + r/100) once per period. Two years at 10% is a 21% rise, not 20%.
Shortcut. Add 10% twice, the second 10% also on the first year's gain: 5,000 + 5,000 + 500 = 10,500 added, giving 60,500.
Common trap. 60,000 — adding 20% as simple growth; the second year's 10% is on 55,000, not 50,000.