If a population growing exponentially double in size in 3 years, what is the intrinsic rate of increase (r) of the population?
If a population growing exponentially double in size in 3 years, what is the intrinsic rate of increase (r) of the population?

Solution: If food resources are adequately available to individuals in a population, it grows exponentially. To estimate the exponential growth, we can use the integral form of exponential growth equation, which is as follows:

{{N}_{_{t}}}={{N}_{o}}{{e}^{rt}} ———-equation (1)

Where Nt is the population density after ‘t’ time

No is the population density at time zero

e is the base of natural logarithm = 2.71828

r is the intrinsic rate of natural increase

Let the current population density be ‘x’

∴ The population density after two years will be 2x and t given is 3 years

Substituting these values in equation (1)

NCERT solutions class 12 biology chapter 13 - 1

Therefore, the intrinsic rate of natural increase of the population is 0.2311