What is the riddle which can be asked all day with a different correct answer each time.

What brings you down but never up?

This puzzle is for Harry Potter fans. Do you know why Tom Riddle is called Lord Voldemort?

Count the Triangle in the figure given below:

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 ?

What is the relationship between these matchstick pictures below?

I have nine bottles of wine and one of the nine bottles is poisoned.
I need to find the poisoned bottle with two facts
(1) Poison is deadly, only a sip will cost death
(2) I have two mice to do so.

How should I do it?

Which number should replace the question mark?

Name a key which is hardest to turn.

There are 20 people in an empty, square room. Each person has full sight of the entire room and everyone in it without turning his head or body, or moving in any way (other than the eyes). Where can you place an apple so that all but one person can see it?