15. A note for $3500 was made at 8% per year compounded annually for 3 years. Find (a) the maturity value and (b) the present value of the note assuming 5% per year compounded semiannually.

16. Computers, Inc., accepted a 2-year note for $12,540 in lieu of immediate payment for computer equipment sold to a local firm. Find (a) the maturity value given a 10% rate compounded annually and (b) the present value of the note at 6% per year compounded semiannually.

** help me to solve this, with explanation in words/ excel please.