Answer:
It will take the 20 years for the population to quadruple.
Step-by-step explanation:
Exponential population growth:
An exponential model for population growth has the following model:

In which P(0) is the initial population and r is the growth rate, as a decimal.
It grows with a doubling time of 10 years.
This means that
. We use this to find r. So



![\sqrt[10]{(1+r)^10} = \sqrt[10]{2}](https://tex.z-dn.net/?f=%5Csqrt%5B10%5D%7B%281%2Br%29%5E10%7D%20%3D%20%5Csqrt%5B10%5D%7B2%7D)


So


Determine how long it will take for the population to quadruple.
This is t for which P(t) = 4P(0). So







It will take the 20 years for the population to quadruple.