Question

Population of a town in 2003 was 10000. If in 2004, there is increment of 15%, in 2005, there is decrement of 35% and in 2006, there is an increment of 40%, then find the population of city at the end of year 2006?
1. 7475
2. 11564
3. 9315
4. 10645
5. None of these

Answer 1

Correct Answer - Option 4 : 10645

Given:

Population of a town in 2003 was 10000

In 2004, there is increment of 15%,

In 2005, there is decrement of 35% and

In 2006, there is an increment of 40%

Calculation:

Population of a town in year 2013 = 10000

Increment of population in year 2004 = 15%

⇒ increased population in 2004 = \(\frac{{115}}{{100}} \times 10000\) 

⇒ 11500

Decrement of population in the year 2005 = 35%

⇒ decreased population in 2005 = \(\frac{{65}}{{100}} \times 11500\) 

⇒ 7475

Increment of population in the year 2006 = 40%

Increased population in 2006 = \(\frac{{140}}{{100}} \times 7475\) 

⇒ 10465

∴ Total population of a town end of the 2006 will be 10465

Short trick:

Total population of a town end of the 2006 will be = \(10000 \times \frac{{115}}{{100}} \times \frac{{65}}{{100\;}} \times \frac{{140}}{{100}}\) 

The total population of town = 10645