Question

the population of a town increased by 10% annually if the percent of the present population is 12000 find its population year ago

Answer 1

Let the population of the town a year ago be x.

So the population at present would be x+ 10% of x (as the population is increased by 10% every year)

⇒x+x×$\frac{10}{100}$ = 12000

x+x/10=12000

11x=120000

x=1,20,000/11=10,909 (approx.)