Rule of 72 Approximately how many years does it take to double a $300 investment when interest rates are 8% per year?
A) .11 years
B) 4.17 years
C) 9 years
D) 11 years

Question

Quizplus · Accepted Answer

The Rule of 72 is a simple way to estimate the number of years required to double an investment at a given annual interest rate. By dividing 72 by the interest rate (8%), you get approximately 9 years.

Rule of 72 Approximately How Many Years Does It Take