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.

If you paint a brown house white it will become a white house. If the stoplight changes from red to green, then the light is green. So, if you throw a white shirt into the Red Sea, what will it become?

It comprises roots which nobody sees,
Much taller than those trees,
Up and up it goes,
Still it never grows?

What is the four-digit number in which the first digit is one-third the second, the third is the sum of the first two, and the last is three times the second?

I have teeth but i don't bite. Who Am I ?

A red house is made out of red bricks. A yellow house is made out of yellow bricks. And, a blue house is made out of blue bricks. So, what is a greenhouse made of?

I am white when I am dirty, and black when I am clean. What am I?

You see me once in June, twice in November, and not at all in May. What am I?

John replied, when asked how old he was. In 2 years he will be twice as old as he was five years ago.' How old is he ?

I can write cow in 13 letters.

Can You?