Question

A town has a population of $17000$ and grows at $4\%$ every year.

What will be the population after $5$ years, to the nearest whole number?

Answer 1

Calculate the population after $5$ years :

The formula for the compound interest is $A=P{\left(1+\frac{r}{100}\right)}^n$where $A$ is the amount, $P$ is the principal, $r$ is the rate and $n$ is time in years.

Substitute $17000$ for $P$, $4$ for $r$ and $5$ for $n$ in the equation $A=P{\left(1+\frac{r}{100}\right)}^n$.

$$\begin{gathered} A=17000{\left(1+\frac{4}{100}\right)}^5 \\ \Rightarrow A=17000{\left(1.04\right)}^5 \\ \Rightarrow A=17000\times 1.2167 \\ \therefore A\approx 20683 \end{gathered}$$

Hence, the population will be $20683.$