Question

Mark (✓) against the correct answer:
The annual rate of growth in population of a town is 5%. If its present population is 4000, what will be its population after 2 years?
(a) 4441
(b) 4400
(c) 4410
(d) 4800

Answer 1

(c) 4410

Present population =4000
Rate of growth = 5%

To find the population of the town after 2 years, we have:

$$\begin{gathered} A=P\mathit{}\times {\left(1+\frac{R}{100}\right)}^n \\ =4000\times {\left(1+\frac{5}{100}\right)}^2 \\ =4000\times {\left(\frac{105}{100}\right)}^2 \\ =4000\times \left(\frac{21}{20}\right)\times \left(\frac{21}{20}\right) \\ =\left(10\times 21\times 21\right) \\ =4410 \end{gathered}$$