5-12 EFFECTIVE RATE OF INTEREST Find the interest rates earned on each of the following a. You borrow $720 and promise to pay back $792 at the end of 1 year. b. You lend $720 and the borrower promises to pay you $792 at the end of 1 year. c. You borrow $65,000 and promise to pay back $98,319 at the end of 14 years. d. You borrow $15,000 and promise to make payments of $4,058.60 at the end of each year for 5 years. 5-13 TIME FOR A LUMP SUM TO DOUBLE How long will it take $300 to double if it earns the following rates? Compounding occurs once a year. a. 6% b. 13% c. 21% d. 100% 5-14 FUTURE VALUE OF AN ANNUITY Find the future values of these ordinary annuities. Compounding occurs once a year. a. $500 per year for 8 years at 14% b. $250 per year for 4 years at 7% c. $700 per year for 4 years at 0% d. Rework parts a, b, and c assuming they are annuities due. 5-15 PRESENT VALUE OF AN ANNUITY Find the present values of these ordinary annuities. Discounting occurs once a year. a. $600 per year for 12 years at 8% b. $300 per year for 6 years at 4% c. $500 per year for 6 years at 0% d. Rework parts a, b, and c assuming they are annuities due