population rate The population of a particular country has a

population rate

The population of a particular country has a doubling time of 50 years. When will the population quadruple its present value? Assume that the historical growth rate of the human population was small but constant at 1.2% per year. For a population of 7.35 billion in 2015, determine the time (year) in the past when the human population was only 3 billion. Then compare your answer with what an internet search engine gives you for population in that year.

Solution

Answer 2

Let the present population be x

After 50 years it will be 2x (given)

Now again after 50 years it will again twice i.e. Twice of 2x

It means it takes 100 years to quadruple its current value