what formulas do i use & how do i show work without using excel ? 12-15

11) Betty borrows $60,000 at 12 percent compounded annually. The loan is to be repaid in five equal annual end-of-year installments. How much must each loan payment be? (5) 12) If the interest rate is positive, a six-year ordinary annuity of S500 per year must have a present value over S3,000. (5) 13) You borrow $30,000 and agree to pay it off with one lump sum payment of $40,000 in 6 years. What annual rate of interest will you be charged? (5) 14) You wish to accumulate $10,000 by depositing $481.46 per month into a savings account that earns 4.75% compounded monthly. How many monthly deposits must you make? (5) 15) At 6 percent compounded monthly, how long will i take to triple your money