Question

Using the rule of 72, t=72/r, how long will it take for the principal to double with an annual compound interest rate of 6%?

Answer 1

12 years

Explanation:

Answer 2

12 years

Explanation:

r = compound interest rate in percent

t = doubling time in years

t = (72percent years)/(6 percent) = 12 years

As a curious cultural fact, there is a connection between the 72 and the fact that ln(2) = 0.69314718055. The constant is 69.3 for continuous compounding...