Population Increase Calculation:
To determine the annual rate of increase in the population, we can use the formula:

Annual Growth Rate = (Final Population - Initial Population) / (Initial Population) * 100

Given:
Initial Population = 1,00,000
Final Population = 1,20,000

Substituting the values into the formula, we get:
Annual Growth Rate = (1,20,000 - 1,00,000) / (1,00,000) * 100
= (20,000) / (1,00,000) * 100
= 20%

So, the annual rate of increase in the population is 20%.

Explanation:
The annual growth rate is calculated by finding the difference between the final population and the initial population, dividing it by the initial population, and then multiplying it by 100 to express it as a percentage.

In this case, the initial population is 1,00,000 and the final population is 1,20,000. The difference between these two values is 20,000. Dividing this by the initial population of 1,00,000 gives us 0.2. Multiplying this by 100 gives us 20, indicating a 20% increase in population over the given time period.

Conclusion:
Therefore, the annual rate of increase in the population of the town is 20%, not 2%. This means that on average, the population of the town has been increasing by 20% each year over the past decade.

In case of population denominator is 1000