help with this please

Question 13 ( 4 points). You expect that you will work for 40 years from now and then you will retire. To retire comfortably, you will invest $700 a month in a stock account and $500 a month in a bond account. You do that for 40 years. The stock account offers you a rate of return of 12% and the bond account will pay 5%. When you retire, you will combine all your money into an account that pays an 8% return. How much can you withdraw each month from your account assuming a 30-year withdrawal period? Assume that the APR is compounded monthly