This problem called Death in a field: A man is lying dead in a field. Next to him is an unopened package. There is no other creature in the field. How did he die? The clues: If he had been able to open the package, he would not have die.
If this one is too easy , here is another one: A man walked into a bar and asked the barman for a glass of water. They had never met before. The barman pulled a gun from under the counter and pointed it at the man. The man said 'Thank-you' and walked out. Why should that be so? Clue: The man had an ailment.
If you can solve this one easily, here is another one: A man died and went to Heaven. There were thousands of other people there. They were all naked and everyone looked as they did at the age of 21. He looked around to see if there was anyone he recognized. Suddenly, he saw a couple, and he knew that they were Adam and Eve. How did he know? (no Clue on this one!...he...he...) Let me know if YOU can solve it! :-)