Design a process to improve financial picture. Explain using exponential and or logarithmic functions?

No income tax is due on the interest earned in some types of investments. You deposit $35,000 into an account. Which of the following plans is better?
A. (tax free) the account pays 6.25 compounded annually. There is no income tax due on the interest earned.
B. (tax deferred) the account pays 7% compounded annually. At maturity, the earned interest is taxable at the rate of 40%.

Answer: By all means, Option A is better—much, much better than Option B.