21. On July 1, 2020, the worlds population was 7,794,798,739. If the global annual growth rate in population averages 1.1% p.a. over the next 50 years, what will the worlds population be on July 1, 2070?

22. If exactly 45 years ago a gallon of milk costs $0.50 and if, today, a gallon of milk costs $3.50, what was the annual compounded inflation rate in the price of milk (i.e., the p.a. rate) over the past 45 years?

23. What is the future value on the day of the last deposit of 20 annual deposits of $500 per year (first deposit to be made today) given an interest rate of 6.75% p.a.?

24. What is the future value exactly 25 years after the last deposit of 20 annual deposits of $500 per year (first deposit to be made exactly one year from today) given an interest rate of 6.75% p.a.?