On Fri, 10 Aug 2007, James Propp wrote:
Either way, this problem is suitable for a kindergarten entrance exam.
Let me make sure I remember this correctly: A supplies 5L, B supplies 3L, and C supplies $8. Each drinks 8/3L. The water is arguably worth $8 / 8/3L = $3/L. A drank 8/3L of his 15/3 liters, so he needs to be reimbursed for the 7/3L he gave the reporter: $7 B drank all but 1/3L, so he deserves $1. Just to check my reasoning, rather than each person drinking his "own" water, we could give A an IOU for $15 and B an IOU for $9 when they pour their water into the pot. A pays for 8/3L = $8 and is owed $7, B is owed $1. C pays his $8. (Sorry, that seemed obvious to me too, but I wanted to make sure) I suppose we could also make a socialistic argument, since by splitting the water equally they seemed to be accepting some sort of a "from each according to his ability, to each according to his needs" approach. In that case, I'd argue that A, B and C each deserve $8/3. Of course, the problem stipulates that C leaves (perhaps this is symbolic of him living his life to the end without the need for money, since society has provided for all his needs, or perhaps that having experienced brotherhood he no longer desires material goods), in which case the remaining A and B each get $4. The desert setting makes this all the more likely: the author places us in a Death Valley marathon, at the low point of western civilization. All necesseties are critically scarce, yet the people are driven to compete to be first across a meaningless finishing line. Ironic that the water they need so much is their only source of shade. The journalist then fits even better as the outsider bringing enlightenment. Of course, in this case the problem leaves us in an open-ended state. Will A and B be tempted by the ironic capitalist notes? Since there are two of them, and given the eastern motif, it seems not unlikely to me that one would play the yin, perhaps using the notes merely as paper on which to write a poem, and one the yang, eventually being overcome by greed. However, a more optimistic author might have both A and B learn from C's example and give up desire, exemplifying how good flows outward and in so doing, grows. Of course, we'd then need to know how A and B's actions affected D, E, F and G to determine whether the author intended the growth to be of the form 2^n, 2n, or something more exotic. Here, then, is my final answer to the question: A desert burns hot Three travelers share their thirst Enlightening all