Question

Tick the correct answer in each of the following:

The annual rate of growth in population of a town is $10\%$. If its present population is 33275. What was it 3 years ago?

(a) 25000 (b) 27500 (c) 30000 (d) 26000

Answer 1

$\text{Rate of growth in population (R) =}10\%\text{Present population = 33275}\therefore \text{Population 3 years ago = A}÷{(1+\frac{R}{100})}^n=33275÷{(1+\frac{10}{100})}^3=33275÷{\left(\frac{11}{10}\right)}^3=33275\times \frac{10}{11}\times \frac{10}{11}\times \frac{10}{11}=25000\left(c\right)$