A girl was sitting in her hotel room when she heard a knock on the door. She opened the door and found that a man was standing outside. The man said, "Oh! I am really sorry, I thought this was my room." He then walked through the corridor to the elevator. The girl did not know the man. She closed her door and called security asking them to apprehend the man. What made her suspicious of that man? He might have been genuinely mistaken.

You walk into a room and see a bed. On the bed, there are two dogs, five cats, a giraffe, six cows, and a goose. There are also three doves flying above the bed. How many legs are on the floor?

There is an ancient kingdom where every married woman keeps information regarding the fidelity of other men. However, what they don't know is the fidelity of their own husbands. Also, there is an ancient belief that they don't tell each other about the fidelity of their husbands.

On a certain day, the queen of the kingdom declares that she has identified at least one unfaithful man in the kingdom. She allows the wives to identify and gives them authority to kill their husbands if they are unfaithful at midnight.

How will the wives manage it?

It walks on 4 when its young, walks on 2 when it's older, and walks on 3 when its very old?

The person who makes it has no need for it. He who purchases it does not use it. The person who does use it does not know they are. What is it?

When can we add 2 to 11 and get 1 as the correct answer?

Three doctors said that Bill was their brother. Bill says he has no brothers. How many brothers does Bill actually have?

Prove that twice of ten is the same as twice of eleven.

You need to climb ten stairs. At every stair, you can either take one step up or you can jump two steps up.

In how many different ways you can climb 10 stairs?

2, 3, 5, 9, 17, _ What is the next number in the sequence?