What breaks yet never falls, and what falls yet never breaks?
What is the last thing you take off before bed?
What has 13 hearts but no other organs?
If you're 8 feet away from a door and with each move you advance half the distance to the door. How many moves will it take to reach the door?
Why Aeroplane windows are round?
Two-person want to cross a river. Only one boat is present on the riverside that can carry only one person at a time. However, they still manage to cross the river. How is it possible?
Count the number of lines in the image below ?
Six glasses are in a row. The first three are filled with milk and the last three are empty. By moving only one glass, can you arrange them so that the full and the empty glasses alternate?
You measure my life in hours I serve you by expiring I vanish faster when I am thin and slower when I am thick The wind is my energy What am I?
Which flower has two lips?
If in a car race, the man who came two places in front of the last man finished one ahead of the man who came fifth, how many contestants were there?
There is a cryptic organization called Cicada 3301 that posts challenging puzzles online, possibly to recruit codebreakers and linguists.