13. You own an apartment house that provides a net income to you of $2000 per month. What is the maximum 20-year mortgage loan you could obtain such that the payments on the loan could be made entirely from the apartment income? Assume a 9% annual interest rate (0.75% per month) and monthly payments on the mortgage.

(please don't solve using Excel) please use a formula or a financial calculator method, or both. thank you!