The Hen, The Dog and The Cat
A hen, a dog and a cat are stolen. Three suspects are arrested named Robin, Steve and Tim. The police is sure that all of them stole one of the animal but they don’t know who stole which animal.
Sherlock Holmes is appointed to identify and is provided with the following statements from the investigation.
Robin says “Tim stole the hen”,
Steve says “Tim stole the dog”,
Tim says “Both Robin and Steve are lying. I neither stole hen, nor dog”.
Sherlock is somehow able to deduce that the man who stole the cat is telling a lie and the man who stole the hen is telling truth.
Who stole which animal?
Robin stole Cat,
Steve stole Hen,
Tim stole Dog.
Glance at the first and second statement again; they are contradictory. Both can be true together though. Also both of them cannot be false which means that Tim stole cat and his statement will be true. But it has been already deduced that the one who stole cat was telling a lie thus it can’t be possible.
Let us consider the situation again. It may be that Tim stole a hen or a dog. Assume that he stole hen. In such a case the statement of Tim will be false. But we know that the person who stole hen told the truth, thus it is contradicting our assumption and so cannot be correct.
Considering everything, now we can say with confidence that Tim stole the dog.
Now it means that the statement by Robin is completely false and the statement by Steve is true which depicts that the cat and hen are stolen by these two. Also we know that the one who stole hen is true and the one stealing cat is a liar.
Thus we now know that Robin stole cat and Steve stole hen.