Prove that any group of six people contains either 3 mutual friends or 3 mutual strangers.
(For the purpose of this problem any pair of people must be either friends or strangers.)
If there are six people then all six of them maybe friends. So there are 3 people who are friends. If the six people dont know each other then 3 of them are strangers. Either I am right or don't know the meaning of mutual!
(By the way levik, Isn't this a question from an IQ test?)