You decide to open a retirement account at your local bank that pays 10%/year/month (10% per year compounded monthly). For the next 20 years, you will deposit $500 per month into the account, with all deposits and withdrawals occurring at months end. On the day of the last deposit, you will retire. Your expenses during the first year of retirement will be covered by your companys retirement plan. As such, your first withdrawal from your retirement account will occur on the day exactly 12 months after the last deposit.

What monthly withdrawal can you make if you want the account to last 25 years?

what monthly withdrawal can you make if you want the account to last forever(with infinite withdrawals)?