How would you go about evaluating the present value of each of the following?
a. The existing reserves of a relatively small oil company
b. The total world reserves of an exhaustible natural resource with a known completely fixed supply
c. A long-term bond, issued by a very unstable third-world government that promises to pay the bearer $1000 per year forever
d. A lottery ticket that your neighbour bought for $10, which was one of 1 million tickets sold for a drawing that will be held in one year's time paying $2 million to the single winner.