# Estimate the doubling time (in years) for the interest rate

## Question: A) Use the “rule of 72” to estimate the doubling time…

A) Use the “rule of 72” to estimate the doubling time (in years) for the interest rate, and then calculate it exactly. (Round your answers to two decimal places.)

7.9% compounded weekly.

Rule of 72 answer:

Exact answer:

B) You have just won $190,000 from a lottery. If you invest all this amount in a tax-free money market fund earning 6% compounded weekly, how long do you have to wait to become a millionaire? (Round your answer to two decimal places.)

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