retirment problem need excel answers

Assume that you plan to retire in 35 years and that you estimate you will need an income of $150,000 on the day you retire and an equivalent amount at the beginning of each year for a total of 20 yearsAssume that you will earn 11.00% during your working years and 6.00% after you retire. You will donate $500,000 to the local Humane Society 10 years after you retire. How much will you save every month during your working years to meet these goals?

How much must you have saved on the day you retire? Your answer here Hew machmust you save every month to accumulate the amount needed on the dey you raire? Your anwwer hare