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All Puzzles

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26 likes 9.2
(Impossible.)
Three Idols in Logical
Classic: Three gods A, B, and C are called, in some order, True, False, and Random. T...
Added 10 months ago by M2JOHNSON currently with 34 comments
16 likes 6.9
(Challenging)
Crazy Google Interview Question in Lateral Thinking
You are shrunk to the height of a nickel and your mass is proportionally reduced so as ...
Added about 1 year ago by ig0r currently with 32 comments
6 likes 5.0
(Moderate)
Balloon in an Elevator in Unsolved MindCiphs
A person is holding on to a helium balloon in an elevator. The elevator cable snaps, an...
Added 3 months ago by vette982 currently with 24 comments
10 likes 2.7
(Fairly Easy)
Always So Negative in At the Campfire
What question can you never answer "yes" to?
Added about 1 year ago by johnp currently with 20 comments
31 likes 5.1
(Moderate)
Psycho Killer in Lateral Thinking
While at the funeral of her mother, she met a man whom she did not know. She thought he...
Added about 1 year ago by copter currently with 20 comments
36 likes 6.0
(Challenging)
Burning Rope in At the Campfire
There are two lengths of rope. Each one can burn in exactly one hour. They are not ne...
Added about 1 year ago by vette982 currently with 19 comments
24 likes 7.2
(Challenging)
The Famous Hole in a Sphere in Mathematics
This incredible problem was first made famous by Martin Gardner with his 'Mathematical ...
Added about 1 year ago by Valentin currently with 16 comments
13 likes 6.4
(Challenging)
The Monty Hall Problem in Logical
This problem has numerous variations and its various forms has stumped many mathematici...
Added about 1 year ago by johnp currently with 16 comments
14 likes 7.1
(Challenging)
12 Identical Balls in Logical
You have 12 identical balls. One of them is slightly different in weight than the rest...
Added about 1 year ago by kash currently with 15 comments
50 likes 5.2
(Moderate)
The Hidden Tiger in Optical Illusions
This must be the toughest optical illusion I’ve ever come across, created by American w...
Added about 1 year ago by copter currently with 15 comments
14 likes 5.0
(Moderate)
Power of 2 (Microsoft Interview) in Computer Science
Given any number n, using one line of C (using no external libraries or functions) code...
Added 7 months ago by ace currently with 15 comments
11 likes 2.9
(Fairly Easy)
What number is next? in Mathematics
What number comes next in this sequence? 4, 20, 56, 120, 220, ?
Added 5 months ago by ace currently with 15 comments
10 likes 5.0
(Moderate)
The Stealing Mailman in Logical
This is a fairly simple problem that can cause some people trouble. Kevin and Sophia ...
Added about 1 year ago by johnp currently with 14 comments
7 likes 5.4
(Moderate)
Google Interview Question - Databases in General
"Explain a database in three sentences to your eight-year-old nephew." This question...
Added 10 months ago by vette982 currently with 14 comments
6 likes 4.3
(Moderate)
1000 Bottles of Wine on the Wall... in Logical
You are the king of a small dominion. You are receiving a shipment of 1000 bottles of ...
Added 9 months ago by ace currently with 14 comments