Suppose you took out a 15-year mortgage for $140,000, at an annual rate of 5%. After 5 years, the 15-year mortgage rate dropped to 2%, and you decided to refinance at this low interest rate. (a) how much remains to be refinanced on the second mortgage? (b) how much will your monthly payment be? (c) how much do you save (gain) by refinancing? (write the answer up to 2 decimal places .)