If the per capita income of a country is growing at 3.5 percent per year, approximately how long will it take for that income to double?
A) 20 years
B) 25 years
C) 35 years
D) 70 years

Question

Quizplus · Accepted Answer

The rule of 72 is a quick way to estimate the number of years it will take for an investment to double at a given annual rate of return. To use the rule, simply divide 72 by the annual rate of return. In this case, the annual rate of return is 3.5%, so it will take approximately 72 / 3.5 = 20 years for the per capita income to double.

If the Per Capita Income of a Country Is Growing