You expect to receive $$25,000$ at the end of the $10$th year.

a$)$ What is the present value of the above amount today, if the interest rates are as follows: $5\%$ for the first four years, $6\%$ for the following four years, and $8\%$ thereafter.

b$)$ What will be the present value today if in addition to the initial $$25,000,$ you also receive $$10,000$ in year $4$ and $$8,000$ in year $6?$ Assume an annual $6\%$ interest rate for all ten years.

USE EXCEL