Question

If the interest earned by a CD is compounded annually, which rule is most accurate when calculating how long it will take the money invested in the CD to double? (A). Rule of 69 (B). Rule of 72 (C). Rule of 4 (D). None of the above

Answer 1

I believe the answer is: B. Rule of 72

In financing, rule of 72 refers to a method to estimate an investment that being done by dividing the interest percentage annually to obtain the prediction of periods required for doubling. Rule of 72 is usually used when the interest type is common and the number is easily divisible.