Your aunt and uncle are each 62 years old and hope to retire in four years. After retirement they will receive $4000 per month after taxes from their employers pension plans and $4,500 per month after taxes from Social Security. Unfortunately, their monthly living expenses are $15,000. They say that their social obligations preclude further economies. Your aunt and uncle have $945,000 invested in high-grade, tax-free municipal-bond mutual fund. The return on the fund is 3.225% per year. They plan to make monthly withdrawals at the beginning of each month from the mutual fund to cover the difference between their pension and Social Security income and their living expenses. How many years before your aunt and uncle run out of money? How old will they be?

please don't answer in excel form! thank you