Fv=PV x ($1+r/c)^N

PV=FV x 1/($1+r/c)^n -1/r/c

Fv=ANN x ($1 + r/c)^n

PV=Ann x ($1-$1/($1+r/c)^n/r/c

im using these to find the answer to the problem but I don't know which ones to use and solve

5. If you were a banker and a client offered to give you a $200,000 noninterest-bearing note that was due 5 years from today (the note promises to pay you only $200,000 five years from today) how much would you loan them if you wanted to earn an 8% annual interest rate that is compounded quarterly? 6. On July 1, 2008, a customer has agreed to make five $3,000 quarterly payments starting on Oct 1, 2008, and a final payment of $7,000 on July 1, 2011, for a piece of equipment that cost you $12,000. If the annual interest rate is 7% how much profit did you earn on the sale of the equipment