There were two pairs hanging on a tree, one man walked by and took a pair. Soon after a second man also took a pear from the tree. However, even after both men took fruit from the tree there was still a pear left on the tree. How could this be?
Answer: There were four pears (2 pairs) on the tree. The first man took a pair (2 pears) and the second only took one pear leaving one pear on the tree.