Algebra and Trigonometry and Their Applications

Math 148 Autumn Quarter, 2001


Instructor: Sergei Chmutov

Bonus problem. The Rule of 72
10 points extra credit

The rule of 72 allows you to find the number of years required to double your money at a given interest rate compounded annually. See the site "Why it works" for a kind of mathematical explanation and for "The rule of 69" for continuously compounded interest.




Problem:
Find (and provide an explanation) for the similar rules for interest compounded


(Answers should be accurate to three decimal places.)