Question

The population of a town increases 10% annually. If the present population is 22000, find its population a year ago.

Answer 1

Let the population of the town a year ago was=x

Increase in population =10%

$\therefore$ Present population $=x\times \frac{100+10}{100}=\frac{110}{100}x$

$\therefore \frac{110}{100}x=22000\Rightarrow x=\frac{22000\times 100}{110}$

$\Rightarrow x=20000$

$\therefore$ Population of the town a year ago =20000