During the Holocaust there is a jewish man who has managed to evade the nazi soldiers fro many months. He has finally made it to the border of Germany, but to his dismay, there is a massive river blocking his way with only one bridge over. The bridge was under nazi control and any person caught trying to exit Germany will be killed on the spot, but any Polish person caught trying to enter Germany without the proper papers will be sent back to Poland. There is only one gaurd on this bridge and he only checks the bridge for people every three minutes. Now, no matter how quickly any person may run, this bridge will always take exactly five minutes to cross. How can the German man exit Germany without being caught and killed?
Simply, he walks for two minutes and fifty seconds, then turns around and pretends to walk into Germany. The guard comes out and sees him. He walks over to him and asks him for his papers. When he can't produce the proper papers he is sent to poland because the gaurd thought he was a Polish citizen.