A woman is sitting in her hotel room when there is a knock at the door. She opened

Question: A woman is sitting in her hotel room when there is a knock at the door. She opened the door to see a man whom she had never seen before. The man said, “oh I’m sorry, I have made a mistake, I thought this was my room.” He then went down the hallway and in the elevator. The woman went back into her room and phoned security. Why?

Answer: If it would have been the man’s room, he wouldn’t have knocked on the door. He could have used the key-card to open the door. This made the woman suspicious of the man.