Lesson: Exponential Growth and Decay Models

A mathematical model predicts that the population of a country, million, will be given by the formula , where is the number of years since 2015. Use this model to predict the population of the country, to the nearest million, in both 2021 and 2022.

Chloe wants to invest some money. She would like the value of her investment to double in 10 years. Write an equation that can be used to find , the annual rate of interest required. Assume interest is compounded annually.

A population of fruit flies quadruples every 3 days. Today, there were 150 fruit flies in the population under investigation.

Assuming the population continues to grow at the same rate, write an equation that can be used to find , the number of fruit flies expected to be in the population in days’ time.