Your business involves "buying" payouts from lottery winners in exchange for a lump sum. Ignatz Minoki has just won a "$20 million lottery" ($500,000 per year for 40 years).
If you want to earn 10% annually on your money, what is the most you should offer Ignatz in exchange for his signing over the rights to the 40 annual payments to you?
(Assume that the first lottery payment would be received immediately).