A country will roughly double its GDP in twenty years if its annual growth rate is:
A)2.5 percent.
B)3.5 percent.
C)7.5 percent.
D)12 percent.

Question

A country will roughly double its GDP in twenty years if its annual growth rate is:
A)​2.5 percent.
B)​3.5 percent.
C)​7.5 percent.
D)​12 percent.

Quizplus · Accepted Answer

The rule of 72 is a simple way to estimate the number of years required to double the GDP at a given annual rate of growth. Divide 72 by the annual rate of growth to get the approximate number of years. For a 3.5 percent growth rate, 72 divided by 3.5 equals approximately 20.5 years, making option B the closest answer.

A Country Will Roughly Double Its GDP in Twenty Years