Question

The population of a town was 160000 before 3 years. If the rate of growth of population in these three years be 3%, 2.5% and 5% respectively, then find the population of the town at present.

Answer 1

The population of the town was 160000 before 3 years.
`:.` before 2 years, the population of the town was `160000xx(1+3/100)^(1)`
`=160000xx103/100=164800`
Also before 1 year, the population of the town was `164800xx(1+2.5/100)^(1)`
`=164800xx(102.5/100)^(1)=168920`
At last, the population in the present year `=168920xx(1+5/100)^(1)`
`=168920xx(1=1/20)`
`=168920xx21/20=177366`
Hence the population of the town at present is 177366.