Question

The population of a city increases by 30% every year. If the present population is 338000, then what was the population of the city 2 years ago?

Answer 1

population 2 years before be X

So increasing @30%per year present population (using formula for compound interest)

P=X(1+30/100)^2

Or 338000=X(130/100)^2

Or X=338000×10000/130×130

Or X=200000

answer is population before 2 years was 200000