Bank A gives you a $500,000, 20-year fifixed-rate mortgage, to be repaid with 240

level end-of-month payments at 3% nominal annual rate, compounded semi-annually. Right

after your 48th payment, bank B offffers you a 2.5% nominal annual rate, compounded semi

annually, for the remainder of your mortgage. If bank A charges a 4% penalty on the outstand

ing balance for breaking the mortgage, would you switch?