A house is for sale for $250,000. You have a choice of two 20-year mortgage loans with monthly payments: (1) if you make a down payment of $25,000, you can obtain a loan with a 6.5% rate of interest or (2) if you make a down payment of $50,000, you can obtain a loan with a 6% rate of interest. What is the effective annual rate of interest on the additional $25,000 borrowed on the first loan