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?

A tree doubled in height each year until it reached its maximum height over the course of ten years. How many years did it take for the tree to reach half its maximum height?

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

In a football game, Christina defeated Teresa by 2 - 0 but no man from either side scored. How can this be possible?

Without looking at a calendar, within a minute name, a boy's name using 5 consecutive 1st letters of 5 consecutive months

What has six faces, but does not wear makeup, has twenty-one eyes, but cannot see?

Analyze and find the missing item in the sequence:
16, 06, 68, 88, __, 98

You have a three-gallon and a five-gallon measuring device. You wish to measure out four gallons.

When I asked a girl's name she told me her name is the date '07/09/2001'.

I thought for a few seconds and then I got her name. Do you?

You have a 12 liters jug full of water. You have two empty 8 liters and 5 liters jug. How can you divide the water into two equal parts using these jugs?