What will be the approximate population of the Country, if its current population of 250 million grows at a compound rate of 2.5% annually for 20 years?

Assume the total expense for your current year in college equals $50,000. Approximately how much would your parents have needed to invest 18 years ago in an account paying 3% compounded annually to cover this amount?

What is the present value of the following set of cash flows at an interest rate of 7.5%: $2200, today, $2,800 at end of year 1, $5,000 at end of year 3, and $5,000 at end of year 5? $8500 is deposited into an account paying 8% annually, to provide four annual equal amount withdraws beginning in one year (there will be no money left in the account after the last withdraw). How much remains in the account after the first payment has been withdrawn (money is always taken out at the end of the period)? 

Continuing from the previous question, how much money would be left in the account after the second withdraw?