Can someone explain to me how to get all these answers!

c. If you hope to live for 30 years in retirement, how much can you withdraw every year in retirement (starting one year after retirement) so that you will just exhaust your savings with the 30th withdrawal (assume your savings will continue to earn 7.5% in retirement)? The amount you can withdraw every year in retirement is $33,407.62. (Round to the nearest cent) d. If instead, you decide to withdraw $79,000 per year in retirement (again with the first withdrawal one year after retiring), how many years will it take until you exhaust your savings? (Use trial-and-error, a financial calculator: solve for ''N'', or Excel: function NPER) You will exhaust your savings in 6.50 years. (Round to two decimal places) e. Assuming the most you can afford to save is $900 per year, but you want to retire with $1,000,000 in your investment account, how high of a return do you need to earn on your investments? (Use trial-and-error, a financial calculator: solve for the interest rate, or Excel function RATE) You will need a return of 21.65%. (Round to two decimal places.)