Remember that there must be a negative number in your calculations for the formulas to work. If you get an error message on your calculator go back and make one of the dollar variables negative......usually the PV factor 8 . 1. Keenan has won the lottery for $20 million. He is offered a cash payment now of $15 million, or 10 annual payments of $2 million. a. What is the interest rate that makes these two amounts equal? o PV = FV = I = N = Pmt = ANSWER:.