Answer:
[tex]t=7.85 years[/tex]
Step-by-step explanation:
We can write this rate as an ordinary differential equation.
[tex]\frac{dP}{dt}=aP[/tex]
Where a is proportional constant, P the population variable, and t the time.
[tex]\frac{dP}{P}=adt[/tex]
Integrating each side of the equation.
[tex]\int \frac{dP}{P}=\int adt[/tex]
[tex]ln(P)=at+c[/tex]
[tex]P=e^{at+c}[/tex]
[tex]P=e^{c}e^{at}=Ce^{at}[/tex]
To find C we need to use the initial condiction, it means evaluae P at t=0.
[tex]P_{0}=Ce^{0}=C[/tex]
[tex]P=P_{0}e^{at}[/tex]
Now, we use the sentence the population has doubled in 5 years.
[tex]2P_{0}=P_{0}e^{a5}[/tex]
We can find "a" in this condition.
[tex]2=e^{a5}[/tex]
[tex]ln(2)=a5[/tex]
[tex]a=\frac{ln(2)}{5}[/tex]
[tex]a=0.14[/tex]
Finally, let's find how long will it take to triple.
[tex]3P_{0}=P_{0}e^{0.14t}[/tex]
[tex]3=e^{0.14t}[/tex]
[tex]t=\frac{ln(3)}{0.14}[/tex]
[tex]t=7.85 years[/tex]
I hope it helps you!
