As the production manager of HPG, Inc., you have received an offer from the supplier who provides the wires used in headsets. Due to poor planning, the supplier has an excess amount of wire and is willing to sell $750,000 worth for only $600,000. You already have one year's supply of wire on hand. This new wire would be used one year from today. What implied interest rate would your firm be earning if you purchased the wire?

I don't have a financial calculator, so I would like to know which formula I should use to solve for the interest. Is it a future value or present value type of problem?