The population of a colony of mosquitoes obeys the law of uninhibited growth. If there are 1000 mosquitoes initially and there are 1900 after 1​ day, what is the size of the colony after 4 ​days? How long is it until there are 60 comma 000 ​mosquitoes?

Respuesta :

Answer:

a) 13032

b)6.4 days

Step-by-step explanation:

The formula for the population growth is given by

[tex]A=Pe^{rt}[/tex]

Here, A = final population, P = initial population, r = growth rate and t = time

From the given directions, we have

A = 1900, P = 1000, t = 1, r = ?

Substituting these values in the above formula to find r

[tex]1900=1000e^{r\cdot1}\\\\1900=1000e^r[/tex]

Divide both sides by 1000

[tex]\frac{1900}{1000}=e^r\\\\e^r=\frac{19}{10}[/tex]

Take natural log both sides

[tex]\ln(e^r)=\ln(\frac{19}{10})\\\\r=0.64185[/tex]

Therefore, the population model is given by

[tex]A=1000e^{0.64185t}[/tex]

(a) The size of the colony after 4 ​days is given by

[tex]A=1000e^{0.64185\cdot4}\\\\A=13032[/tex]

(B) The time for the number of mosquitoes to be 60,000 is

[tex]60000=1000e^{0.64185t}[/tex]

Divide both sides by 1000

[tex]\frac{60000}{1000}=e^{0.64185t}\\\\e^{0.64185t}=60[/tex]

Take natural log both sides

[tex]\ln(e^{0.64185t})=\ln60\\\\0.64185t=\ln60\\\\t=\frac{\ln60}{0.64185}\\\\t=6.4[/tex]

Hence, it will take 6.4 days to the population of mosquitoes to be 60000.