16 Jun '04 14:24>2 edits
Mr and Mrs Jones invite, four couples to a dinner party - the Whites, the Clarkes, the Greys, and the Browns. Some of the people have met before and some haven't. When they arrive All the people who haven't met before shake hands, and then Mr Smith asks each of the guests and his own wife how many hands they each shook. He receives a different answer from each person he asks. How many hands did Mrs Jones shake? (You may assume that everybody has met his own spouse before.)