Question: You are a prisoner. The only way to escape the prison is to walk down a very long hallway that takes 2 hours to get through. Guards come out of a door halfway down the hall every hour and take any prisoners walking out back to the prison and escort any visitors out of the prison. The guards cannot tell the difference between prisoners and visitors.
How do you escape?
Answer: Walk for about an hour and when you see the guard door open turn the other way and walk towards the prison. They will think you are a visitor and escort you to freedom.
Question: Your friend tells you about a story he once tried to impress a young lady with, but instead got a slap in the face. He wants you to attempt to see the flaw: It was a hot and windless day, in our bunker, when suddenly one of ours yelled: "Enemy!" We opened fire on them, leaving one hundred of them dead before they retreated. I was checking a dead captain's glasses when the shout came that they were incoming again, and the CO ordered us to open up on them with our mortars, when I yelled: "Cease fire! They're Americans!" Later, an American colonel thanked me for my work after I said that I saw their flag, waving back and forth in the wind. What is wrong with this story?
Answer: At the beginning, it was said that "It was a hot and windless day," yet at the end, it is said that "The flag was waving back and forth". Had it been windless, the flag would have been limp.