Answer:

Step-by-step explanation:
We can write this rate as an ordinary differential equation.

Where a is proportional constant, P the population variable, and t the time.

Integrating each side of the equation.



To find C we need to use the initial condiction, it means evaluae P at t=0.


Now, we use the sentence the population has doubled in 5 years.

We can find "a" in this condition.




Finally, let's find how long will it take to triple.




I hope it helps you!
Use arccos...cos^-1 so
cos^-1 (0.8195)
it equals 34.96522689°
Answer:

Step-by-step explanation:
From the Venn diagram, n(AUB)=31
The given probabilities in the option are calculated below:

The only correct option is the probability of B which is 
C=2pir
20pi=2pir
20pi/2pi=2pir/2pi
R=10
Height=10/2=5
Two circles surface areas is
2*pir^2
2pi10^2
2*100pi
200pi
The cylindrical part is
2pirh
2pi*10*5
100pi
Add 100pi+200pi=300pi
Answer:
11 years
Step-by-step explanation:
7200 - 80x = 5000 + 120x
-5000 + 80x -5000 + 80x
2200 = 200x
11 = x