Problem
Today is Dec. 31, 2020. David is planning to retire in 40 years from today. He believes he needs to save some money to support his living for at least 20 years, i.e., 2061 through 2080, after his retirement. David estimates that he will need $50,000 each year from Jan. 1, 2061 to Dec. 31, 2080.
Assume that the interest rate is 10% and will be constant over time.
Suppose that David wants to save money starting from one year from today. How much at the end of each year from 2021-2060 does he need to save?