One of the riddles is, "what is as big as you are and yet never weigh anything" with the answer being "your shadow". Another is, "Paul's height is 6 feet and is an assistant at the butcher's shop wearing size 9 shoes. What does he weigh" with the answer being "meat". Get more from http://www.buzzle.com/articles/hard-riddles-good-brain-teasers.html.
On my way to St. Ives, I met a man with seven wives. Each wife had seven sacks, Each sack had seven cats, Each cat had seven kits- Kits, cats, sacks, and wives, How many were going to St. Ives? Answer: One. On his way to St. Ives, he met the man. Therefore, the man was going in the opposite direction, away from St. Ives.