The population of a village is 20000. If the rate of birth be 4% per annum and the of death be 2% per annum, then find the population of the village after 2 years.

Explanation

Rate of birth `=4%` per annum.
Rate of death `=2%` per annum.
`:.` Rate of growth of population `=(4%-2%)` per annum
`=2%` per annum
The present population of the village is 20000.
`:.` The population of the village after 2 years will be `20000xx(1+2/100)^(2)=20000xx(1+1/50)^(2)`
`=20000xx(51/50)^(2)=20000xx(51xx51)/(50xx50)`
`=20808`.
Hence the required population of the village after 2 years will be 20808.