Question

The population of the world grows exponentially at a rate of 1.1% per year.
Find the number of years it takes for the population to grow from 7 billion to 7.31 billion.
Give your answer correct to the nearest whole number

Answer 1

Here is what I have so far, not sure if it's correct but here it goes:
I used the compound interest formula : A = P*(1+r/100)t
where:
P= principle amount
r= percentage rate
t=time
A= ending amount

Then substituted in values: 7.1 = 7*(1+(1.1/100))t