Approximately what interest rate is needed to double an investment over eight years?
A) 8 percent
B) 9 percent
C) 12 percent
D) 100 percent

Question

Quizplus · Accepted Answer

The rule of 72 is a simple way to estimate the number of years required to double the investment at a given annual rate of return. By dividing 72 by the annual rate of return, investors can get a rough estimate of how many years it will take for the initial investment to duplicate itself. In this case, 72 divided by 8 years equals 9 percent, which is the approximate interest rate needed to double an investment over eight years.

Approximately What Interest Rate Is Needed to Double an Investment