Question

in 1996 the population of a country was 65 million and growing at 4.2% per year.  

1. Let P(t) represent the population t years since 1996. write the exponential function rule for P(t) that models the population of the country. 
2. use your function to predict the population of the country in 2006. show your method
3. use your calculator to estimate the first year in which the country`s population will be at least double the population in 1996. show your method.