Exponential Population Growth: 1970-1980

[jackleyt]

Homework Statement

The population of a country is growing exponentially. The population in millions was 120 in 1970 and 150 in 1980.

(a) What is the population t years after 1970?

(b) How long does it take the population to double?

(c) When will the population be 400 million?

Homework Equations

The Attempt at a Solution

I don't know how to start the equation, so I listed out the years and the populations to no avail.

 

[djdoug99]

I'll give you the equation you need to use.

P(t) = P₀e^kt

P(0) = P₀

Use the information given in the problem to find your constant (k). Once you have that it is very easy.

Cool, first post!