Question

Taylor County, which has a population of 21,000 people, has been experiencing populationdecline of 10% every year. Assuming this continues, what will the population be in 2 years?

Answer 1

Population of Taylor County is 21000

The population declines by 10% every year

Since it declines by 10% everywhere i.e the declination is at a constant percentage, the population left after every year in % will be

$100-10=90\text{\%}$

Let n represent the number of years,

To find the population left, the formula is

$\begin{gathered} \text{Population left}=21000(\frac{90}{100})^n=21000(0.9)^n \\ \text{Population left}=21000(0.9)^n \end{gathered}$

For two years, i.e n = 2

The population left in 2 yearswill be

$=21000(0.9)^n=17010$

Hence, the population left in 2 years is 17010