Refer back to Section 3.2. If the rate of interest is 8 percent rather than 10 percent, how much would our benefactor need to set aside to provide each of the following?

a. $100,000 at the end of each year in perpetuity.

b. A perpetuity that pays $100,000 at the end of the first year and that grows at 4 percent a year.

c. $100,000 at the end of each year for 20 years.

d. $100,000 a year spread evenly over 20 years.