Alice and Bill threw a party and invited four other couples. As each couple arrived there were greetings, including handshakes.

Later in the evening, Bill asked everyone, including Alice how many people they shook hand with. Every answer was different. No one shook hands with his or her own partner.

How many hands did Alice shake?

the answer is 4, I think... 

Posted by Assaf on 2007-02-28 08:13:56