# All Questions

19,633 questions
Filter by
Sorted by
Tagged with
1k views

### 16 Buttons, Turn them all Red or Green?

There's 16 buttons arranged in a 4 by 4 square. They are coloured either red, or green. They appear like this (red being 1, green being 0) 1010 0101 1100 0011 Each press will switch all the ...
417 views

### Abalone Migration

Abalone is a 2-player board game. Here's a brief explanation from Wikipedia: The board consists of 61 circular spaces arranged in a hexagon, five on a side. Each player has 14 marbles that rest in ...
2k views

### A puzzle of trust and lies, allies and spies

Here is a puzzle involving distrust and asymmetric knowledge. (It was inspired by, but not exactly following, the board game The Resistance: Avalon.) There are ten resistance fighters trying to ...
3k views

3k views

### Water glass and wine glass [duplicate]

You have two equal glasses. One is filled with water. One is filled with wine. Now you take a spoonful from the water glass, put it into the wine glass, and stir until it is well mixed. Then you take ...
6k views

### Poisoned Bottle of Wine! [duplicate]

This puzzle is taken directly from a site and reworded. The site can be found at the bottom of this question. You are king of an empire and you are going to have a party soon. The party is the most ...
13k views

### 7 Trees, 6 Rows, 3 Per Row?

Can you arrange 7 trees so that there are 6 rows of 3 trees? It is entirely possible. Note: A tree can be part of more then one row, for example a if you arranged a 3x3 square (9 trees) the tree in ...
17k views

### Is the Glass Half Full with water?

You, a right cylinder glass of water, 3 buttons, instructions, and a large flat land that seems to go on forever, are the only things that exist in a universe. In this weird universe, the exact same ...
383 views

### Dominoes on a Chess Board [duplicate]

Imagine an 8x8 chessboard has two opposite corners taken out, with 62 squares left over. Is it possible to lay 31 dominoes with the size 2x1 so they cover all of the empty, left over, squares?
7k views

### Can you Turn MI to MU?

Using the letters M, I, and U, which can be used to create words. Can you turn MI into MU using in each step one of the following rules: Insert a U to the end of a word ending in I. e.g: MI becomes ...
10k views

### How many paths are there through a chess board? [closed]

A pawn is placed on the lower left corner square of a standard 8 by 8 chessboard. A 'move' involves moving the pawn, where possible, either: one square to the right, one square up, or diagonally one ...
2k views

### Directions on an infinite compass rose

An old sailor, by the name of John, was in his attic with his bright young great-nephew Stewart, showing him all the old tools they used to use while at sea. Stewart was fascinated by all the ...
329 views

### Largest No-Capture Setup?

Think of a Chinese Game Board, and how you can make jumps. Now think of actual checkers where you capture pieces. How many marbles can you place without a capture possible? There's one slight rule to ...
782 views

Scott is an expert outdoorsman, pursuing his dream by living in the remote Alaskan wilderness. Scott has everything he needs, and would prefer to remain a recluse, yet he will have to leave his home ...
7k views

### How do I arrange pencils so they all touch each other?

How do you arrange 6 pencils so that each one touches the other five? And what about 7 or 8?
1k views

### Are you a Detective

A detective friend of yours was trying to find clues for a crime he was investigating, he was almost done but a concluding location will help you close the case. Unfortunately your friend could only ...
4k views

### The Dragon or the Magnifying Glass?

You've been sent to prison, but the prisons where you are from are very clever. They do not just lock you up, they put you in a room with 2 doors. Door A is guarded by an evil dragon that will kill ...
978 views

### Social Engineering (The Birthrate Problem)

The distant country of Toomalia has a birthrate of 67 boys for every 33 girls. In an effort to restore a 50:50 gender ratio in the country, Toomalian policymakers institute a mandatory new social ...
2k views

### A Drawer of Socks

Bob wakes up one morning, and he needs to grab a pair of socks for work. In his sock drawer, he has 5 pairs of blue socks, 3 pairs of red socks, and 4 pairs of white socks (Bob is American and very ...
2k views

### How do we get those dang Illuminati?

The Illuminati just stole our office They shot JFK and have committed numerous crimes against humanity (not really) but we usually let that slide. But for stealing our offices, we have decided to ...
2k views

### The Illuminati and the Knights Templar

Some people in the American Senate are working for secret organizations. Some work for the Illuminati, some work for the Knights Templar, and some work for both. The are also innocent citizens who are ...
904 views

### The generous team puzzle

An intelligent team, ‘Smarty Pants’, applying to a competition completes an evaluation form early. Since they are feeling generous they randomly spread their assignment to all 10 teams applying from ...
1k views

### The way to Acarien, with Knights and Knaves

Once again, you're on your way to Acarien. You find yourself in a land of Knights and Knaves, who understand your language but don't speak it. You understand nor speak their language, but you do know ...
3k views

### Are you Really Smart

The government has introduced a standardised test to identify dumb people and make them ineligible to apply for any government jobs, a pass in the exam is mandatory for applications in future. It ...
2k views

### The way to Acarien puzzle

You are on a quest to the find the lost kingdom of Acarien. On your way, you end up at a fork in the road. Both paths look exactly the same. At the junction sits a wise man. The wise man will only ...
20k views

### A double-agent with a conundrum

You are a double-agent in the most important war of the 20th century, The Falklands war. For years you have been playing the United Kingdom and Argentinian governments against each other, taking ...
2k views

### Crack the Code #4

The park bench has been compromised as a safe location, so you decide to meet in the lobby of the nearest hotel. Again, the envelopes are traded securely, along with the money you are receiving for ...
1k views

### Crack the Code #3

You return to the bench after cracking the last code, and you notice an envelope on the ground directly under it. You put down your envelope with the previous code and pick up the new one, ...
476 views

### Confusing, Seemingly-Impossible, yet Correct sentence

What does this mean? "The girl that a man that a dog that a complex that a landlord that a friend that a cat plays with helps owns houses loved seen plays piano." Can you make any sense out of this?
6k views

### Third, Fourth, Fifth [closed]

A friend of mine made a simple bar bet, in which he wrote down a list of ten words. Turning it around to show me, he covered up the first two words with his hand. The eight words below his hand were ...
339 views

### Apples and Oranges

You were on a grocery shopping day, you go to the store, and your friend tells you he'd like you to pick him up some fruit, naturally you try and be a kind friend and agrees to pick it up for him, you ...
3k views

### House Number Mastermind

I was having a house-leaving party at my old house, and challenged four of my friends to guess the number of the new address, which had three digits. The responses I got were 280, 376, 304, and 370....
4k views

### Is my sibling a sister [duplicate]

A male friend of yours wants to test if you are ok at Math and logical thinking, he says I am one of two children of my parents, and asks you to find out the probability that his sibling is a sister, ...
3k views

### Crack the Code #2

After the last bank encounter, you decide that you could make a living off of just cracking codes (as if robbing banks wasn't enough). A shady man meets you on a park bench and slides you an envelope, ...
4k views

### Ernie's automatic parking valet

I was helping Ernie out in his shed a while back, when his favorite screwdriver suddenly wore out. I offered to go and pick up a new one for him and Ernie thought it was a great opportunity to test-...
3k views

### Crack the Code #1

You are a bank robber, and you come across a safe. It has a combination lock of 4 digits. Careful research (and stealing papers at the bank) has given you multiple clues as to the code - just barely ...
7k views

### Flip a Fair Coin

I found this question and became curious, can anyone tell me the answer and prove it, i know it seems fairly simple but just thought an explanation of this would make an interesting case. Flip a fair ...