It is known that a certain kind of algae in the Herring Sea can double in population every 4 days. Suppose that the population of algae grows exponentially, beginning now with a population of 3,000,000.

How long it will take for the population to quadruple in size? in terms of days

Question

It is known that a certain kind of algae in the Herring Sea can double in population every 4 days. Suppose that the population of algae grows exponentially, beginning now with a population of 3,000,000.


How long it will take for the population to quadruple in size? in terms of days

kainui · Answer

The doubling time is the amount of time it takes for the initial population to become double. So after 4 days a population of 7 would become 14. Now if you look at the population of 14 you can use that as the initial population again, and 4 days later you'll end up with a population of 28. So overall it doubled twice, which is the same as quadrupling, right?

anonymous · Answer

when t=4days , the population doubles
therefore when t=8days it will quadruples..ans