If it will take 10 years for a nation's income to double, then its growth rate must be 7%.

Question

Quizplus · Accepted Answer

The rule of 72 is a shortcut to calculate the approximate number of years it takes for an investment to double in value at a given annual rate of return. The rule states that the number of years it takes for an investment to double is approximately equal to 72 divided by the annual rate of return. In this case, the annual rate of return is 7%, so the number of years it takes for the nation's income to double is approximately 72 / 7 = 10 years.

If It Will Take 10 Years for a Nation's Income