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?

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

The doctor advised his patient to take a tablet after every fifteen minutes. He gave him five tablets in total.

How much time will he take to have all the five tablets?

In a jungle where there are no street lights or any other artificial source of lights, I notice a black snake crossing the road.
How did I get sight of the snake?

The more it dries, the wetter it becomes. Can you tell what it is?

10+10 and 11+11 can give you the same answer.

Explain how?

What do you answer even though it never asks you questions?

You see a boat filled with people, yet there isn’t a single person on board. How is that possible?

Suppose we lay down two cups in front of you. One of the cups is filled with tea and the other one with coffee. Now we ask you to take a spoonful of tea and mix it with the coffee. At this moment, the coffee cup has a mixture of tea and coffee. You have to take that mixture (spoonful) and add it back to the tea.

Can you now tell if the cup of coffee has more tea or the cup of tea has more coffee?

You walk into a room that contains a match, a kerosene lamp, a candle and a fireplace. What would you light first?