At times a firm may wish to know at what price it would have to sell its product for a particular investment to have a positive NPV. To determine this price, express the operating cash flow in terms of price. Write out the expression for the NPV using the appropriate discount rate. For the longer operating period, one can calculate an annuity factor to multiply by the operating cash flow expression. Solve the expression for the cash flow that would result in an NPV of zero. Since the operating cash flow was written in terms of price, the price now can be found.