5.

(Please if you are not willing to answer the question completely, leave the question to someone who will!)

a. How long will it take for $ 500 to amount to $ 700, if you invest in the 8% compound quarterly?

b. A debt of $ 600 that must be paid within three years and another of $ 800 payable in four years, will be settled by means of a payment within two years. If the interest rate is 8% compounded semiannually, how much is the payment?