“Five Down”: Solution
Solution to Five Down:
“Since the identical counterfeit bill can be traced through all the transactions, these are all invalid. Therefore everybody stands in relation to his debtor just where he was before the banker picked up the note, except that the butcher owes, in addition, $5.00 to the farmer for the calf received.”
Update: A number of perceptive people have written in questioning Dudeney’s solution, and after some thought I’m inclined to agree with them. The intermediate transactions can stand as they are: Each participant has lost $5 (by accepting a fake bill) and gained $5 (by using it to pay a debt). But the banker has gained $5 (by finding and spending a bad bill), and the bank has lost $5 (by accepting it as good). So if the banker now pays $5 to the bank, all is well.
This puzzle first appeared in The Strand in 1917, and it’s appeared in various collections since then, but I have not seen these objections raised until now. This means I have the best readers in the world.
