please help me using excel!!

4. For each of the following cases, calculate the present value of the annuity, assuming that the annuity cash flows occur at the end of each year. Case Annuity Payment Interest Rate (%) Periods (years) A $10,000 10 5 B $20,000 12 10 5. In the following case the mixed end of period cash flow stream has an annuity embedded within it. Calculate the present value of the cash flow stream, assuming a 10% discount rate. Year Cash Flow JaWN- 1 2 3 4 5 6 7 $10,000 $8,000 $5,000 $5,000 $5,000 $5,000 $3,000