Use geometric sums to find out how much you will need to put away monthly at 3,6,9, and 12% (compounded monthly) for you to reach your desired amount of retirement money. Show all work. Compare what happens at the different rates. You will need your current age 22 , age 22 when you want to retire, and how much you want to have saved up for retirement. Use present value of an annuity (not lump sum up front). Don't forget that this is compounded monthly. Also, it is a finite geometric sum.