a. $10,000 to be received 20 years from today. b. $15,000 to be received annually for 10 years. c. $10,000 to be received annually for five years, with an additional $12,000 salvage value expected at the end of the fifth year. d. $30,000 to be received annually for the first three years, followed by $20,000 received annually for the next two years (total of five years in which cash is received)