Prolog - Inspector Reynolds of Scotland Yards, in search of the "Fountain of youth", arrives at the Island of Knight and Knaves. Only 2 kinds of ppl live in this island ,as u might have already guessed, the Knights and the Knaves .Knights always speak the truth. Knaves always lie. There was a rumor that the "Fountain of Youth" lies in this island, drinking the water of which will bring about Reynold the immortality, he always dreamt of. Le Grande Metapuzzle - The following day, Reynolds came across two natives A and B and said to them,"Please tell me whatever you know about the Fountain of Youth. Is it on this island ?" The two natives then made the following statements: A: If B is a knave,then the Fountain of Youth is on this island. B: I never claimed that the Fountain of Youth is not on this island. Reynold thought about this for a bit and said, "Please, now, I want a definite answer!Is the Fountain of Youth in this island?" One of the two answered - he either said yes or he said no - and Reynolds then knew whether or not the Fountain of Youth was on the island. Some months later, Reynolds told the above facts to Inspector Craig. Craig said,"It is obviously impossible for me to deduce from the facts you have given me whether or not the Fountain of YOuth is on this island. You haven't told me whether A or B was the one who answered your second question, or what answer he gave.Whichever one it was who answered, suppose the other one had answered instead.Do you know if you could then have decided whether or not the Fountain is on the island ?" Reynolds thought about this and finally told Craig whether or not he knew whether he could have decided had the other one answered the second question instead. "Thank you," said Craig."I now know whether or not the Fountain of Youth is on the island." Is the Fountain of YOuth on the island? ----------------------------------------------------- Yes, the fountain is on the island. Reasons -(1)- A said "Yes" ~Then A is Knight and and B is Knave. Because: If A is Knave, He has said ""If B is a knave,then the Fountain of Youth is on this island." i.e. If B isn't knave, then fountain of youth is on the island. and B has proclaimed "I never claimed that the Fountain of Youth is not on this island." Now, A can't support B by saying "Yes" as A will be telling a truth, as prologue goes: *Inspector Reynolds of Scotland Yards, in search of the "Fountain of youth", arrives at the Island of Knight and Knaves. Only 2 kinds of ppl live in this island ,as u might have already guessed, the Knights and the Knaves .Knights always speak the truth. Knaves always lie. There was a rumor that the "Fountain of Youth" lies in this island, drinking the water of which will bring about Reynold the immortality, he always dreamt of. * -(2)- A said "No" ~Then A is Knave and B is Knight Because: If A is Knight, he has said "If B is a knave,then the Fountain of Youth is on this island."And B has proclaimed "I never claimed that the Fountain of Youth is not on this island." i.e. He has always claimed "The fountain of youth is not on the island". i.e. The fountain is on the island, Then A can't say "No" i.e Speak Lie. -(3)- B said "Yes" ~Then B is Knight and A is Knave. Because: If B is Knave, he has said "I never claimed that the Fountain of Youth is not on this island.".i.e.: he always claimed "It is not in the island". Now When He says "Yes" because He will be speaking truth. -(4)- B said "no" ~Then B is Knave and A is Knight. Because: If B is Knight, He has said "I never claimed that the Fountain of Youth is not on this island.". Then he can't say "No" and deny the fact he has already stated. Thank you...Hope its the solution...अलि लामो छ है पढ्नु होला तै पनि!!!;) Nirman~*