True or False?
"This sentence is false." Is the sentence true or false?
Hint: If the sentence is true, it is telling the truth that it is false. If it is false, it is lying that it is false so it is really telling the truth.
Solution: Unfortunately, there isn't really a good solution. Whether the sentence is true or false, a paradox is created. A similar question is, "If a man tries to fail and succeeds, which did he do?"