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

Given,

The present population = 22000

Rate = 10%

Let the population of the previous year be x.

A number of years (n) = 1.

$22000=\mathrm{x}\times \left(1+\frac{10}{100}\right)$

$22000=\mathrm{x}\times \left(\frac{11}{10}\right)$

$\mathrm{x}=22000\times \left(\frac{10}{11}\right)=20000$

Therefore, the population of a town a year ago was 20000.