Question

If the annual growth rate of a population is 2 %, then in approximately how many years will it take for the population to increase by a factor of 4?

Answer 1

Answer: 150 years.

Explanation:

Let the initial population is=X_i

and final population is=X_f

then, according to the definition of annual growth rate of population,

Growth rate=[{(final population-initial population)/(initial population)}*100]/time

   --------------------------------------------------- (1)

According to the question,

%

[since, the final population is increased by 4 times].

So, plugging all the quantities into eqn 1,

.

So, the population will be 4 times of its initial population after 150 years.