3. (Mortgages) Suppose your bank gives you a 30-year mortgage for $300,000. This means that you must pay an amount C at the end of each month for 30 years. Let r12 be the interest rate for the mortgage. Ignore factors like insurance payments, default risk, and so on. From the bank's point of view, this is annuity. Use this idea to find the monthly payment C. Note: There are lots of mortgage calculators online. To receive full credit, you must follow the reasoning asked for in the