please help with 4 and 5

4. Sibley Memorial Medical Center has just received a pledge from a wealthy benefactor to donate $15 million at the beginning of each year for the next 15 years. What is the estimated present value of this contribution if the discount rate is 6%? 5. The heirs to a family fortune have chosen to donate some specified amount to a local non-profit health system. Through their financial advisors, they have offered the provider a choice between the payment of $60,000 per year into perpetuity starting today or a one-time lump sum payment of $700,000 today. Which of the two options is preferable from a present value standpoint if the appropriate discount rate is 5%? Which of the two options is preferable from a present value standpoint if the appropriate discount rate is 13%