Question

A country's current population is 100 million with an annual growth rate of 3.5%. If the growth rate remains constant, what will be the population in 40 years?

Answer 1

395,925,972 or 396 million

Explanation:

Since the population growth rate is 3.5 annual that implies that the increase in population has to be recalculated at the end of each year (i.e. it is not a constant amount like a 100 people or a 1000 people but it changes every year)

To solve this problem we will use the following equation

`P_(t)  = P_(0) (1 + r)^t`

Where

`P_(n)` is population at year 't'

`P_(0)` is initial population i.e. 100 million

`r` is growth rate is a fraction i.e. 3.5/100

`t` is years passed i.e. 40

Now all we have to do is plugin the values

`P_(40)  = 100000000 (1 + (3.5)/(100) )^4^0`

The answer is 395,925,972