Mortgage companies usually charge interest semi-annually. What would be the effective rate of interest on a mortgage at 8.15 percent compounded semi-annually? O a. 8.23 percent O b. 8.32 percent O c. 8.46 percent O d. 8.40 percent If you want to save $1,000,000 for retirement with $200 monthly deposits (end-of-month) at 6 percent interest compounded monthly, how long will it take? O a. 54.4 years O b. 55.9 years O c. 52.8 years O d. 57.2 years