# All Questions

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144 views

### Curved lines on a paper [closed]

There are curved lines drawn on a piece of paper. Lines can have two characteristics: One of its endpoints is on another characteristic 1 line One of its endpoints is on another characteristic 2 line,...
424 views

### Whose lock is lock-ier?

Two friends, Amy and Ben, each use a three-disk combination lock to secure their bikes. Each disk has $10$ orientations, with integers $0$ to $9$, so there are $10^3$ possible combinations. One day, ...
275 views

### Don't worry, I won't byte

... I am pretty hungry though. Figure out what I want to eat: 01001001 00011111 01000100 10110100 11110101 10010001 00011111 01000001 10111101 10110011 01100000 01100110 10000110 11000010 10001000 ...
1k views

### Second star to the right and straight on 'til morning

Remember to look up at the stars and not down at your feet. Try to make sense of what you see... We look up at the same stars and see such different things. So I looked up, second to the right he ...
372 views

### Eureka!: A Riddle

The first one borne, the others belated. Legions have my intentions debated. Headdress upholding my endless mission; I rule either way, death or submission. Gather your might to face my ...
1k views

### The Erasmus polyhedron

Professor Erasmus has constructed a special convex polyhedron from perfectly homogeneous material, which he modestly calls the "Professor-Erasmus-polyhedron". The professor claims that he can put the ...
4k views

### What are my friends' names? (A visual puzzle)

While messing around at one evening, I made six small drawings, one for each friend of mine. My drawings were made to be very specific: Taking the action or object represented in any of them, you can ...
1k views

### An outer-space riddle

Twinkle twinkle little star How I wonder what you are In the sky just passing by You can vanish in the blink of an eye Moving at speeds I can't believe All the things you can achieve In an atmosphere ...
1k views

### A rare sight indeed

Source of an element that never existed Perhaps with thermal tangles Some of us are not as neat Our name is a misnomer An electronic errand? Hard to pinpoint Following death We fade too Question: ...
410 views

### Math sequence puzzle

Complete the sequence: 5928 1411 9909 1882 5419 ... It doesn't seem like a simple polynomial fit will work, I have tried the difference method and the quotient method. Any hint would be appreciated. ...
548 views

### Message to Survivors

Your spaceship pulls out of uberdrive (a new transportation mode that has overtaken hyperdrive in the space exploration market) and you find yourself gazing at the beauty of Earth for the first time ...
2k views

### The London safes and their mysterious combinations

Here's the first riddle I invented for Puzzling SE. Hope you'll enjoy solving it. This story takes place during World War II. A German spy is assigned the task to sneak overnight into a military base ...
180 views

### Round plates on a round table [duplicate]

(I did not make this one up, but it's one of my favorites and I didn't see it on here!) After a long shift at the restaurant, your fellow waiter Jeremiah proposes the following game: Start with an ...
254 views

### N strings in a bag

There are n strings in a bag. In one pass, you randomly pick one end of a string and then one more string. Then you tie these two ends together and put the resulting string back into the bag. Then ...
778 views

The database of mini-facebook only has space for the data of 100 participants. These 100 participants want to establish as many mini-facebook friendships among them as possible. However, mini-facebook ...
529 views

### Knowledge about common knowledge (hats puzzle)

$n$ villagers wear either black or white hats. The truth is that all the hats are black, but this is not known. They sit in a line, so that each villager can see all the hats in front of them, but not ...
1k views

### Make a glass sit above two other glasses using only a regular banknote [closed]

On a table there are three cups and one banknote (a dollar bill will do). These are the only objects you may use, with the goal of placing one of the cups, upright, above the other two, without any ...
1k views

### What is the minimum number of line segments that need to be made to cross all points on a $n \times m$ grid?

Given a grid of $n \times m$ points, on a sheet of paper, what's the minimum amount of lines (which can extend infinitely) required to pass through each point, that you can draw without lifting a ...
170 views

### Flag carrying ants in a ring [duplicate]

There are $n$ ants randomly distributed on a ring facing clockwise or anticlockwise. Each ant is carrying a flag numbered $1,\ldots,n$. They all start moving around the ring at the same speed (in the ...
216 views

### Word Matrices, Level 2

This puzzle is based on NeedAName's recent puzzle, Determinant of Word Matrix. The challenge: Create a $3\times3$ matrix of distinct letters (i.e. no repeated letters) with no vowels in the ...
214 views

### Bob and Steve find an ambiguous sentence - but HOW ambiguous? [closed]

Bob is mentoring Steve at a new job, and they are working their way through some poorly written instructions to install an update for some critical software. Things are going okay up until they find ...
582 views

### What is the largest, compact connected-network polyomino for these tiles?

This is a graphical arrangement puzzle. Consider the following 36 tiles: Each tile has up to 8 connected directions and each tile has an initial up side. (The edge to whose centre the central ...
479 views

### seven thief and equal coins [duplicate]

Seven thieves are to distribute a number of coins between themselves. They find that it splits equally, but being astute mathematicians, they realize that if there were 2, 3, 4, 5, or 6 thieves to ...
471 views

1k views

### Evaporating coins

In the country of Dalgonia, there is only one type of fake coins and only one type of genuine coins. All genuine coins have the same weight. All fake coins have the same weight. Fake coins and ...
725 views

### Empty Rectangles - Does the rule apply when the intersection takes place inside the box with the empty rectangle?

The Empty Rectangles method is a strategy for solving Sudoku puzzles. I have seen the description of this strategy here, I have the following question: Is there a problem if the other end of the ...
730 views

### Numbered Logicians near the Blue Eyes island

There is an island near the famous Blue Eyes island where 100 perfect logicians live, each with a number between 1 and 100 (repetitions allowed) tattooed on their forehead. They know all the numbers ...
355 views

### The Buzzer Game [closed]

Two players, A and B, are each given air horns. Also present is a device which will at some random point produce a noise. If the device produces a noise before either player, they die. If both players ...
872 views

### How to leave me behind

If you wish to leave, then there's no doubt first you must look for the way out. Then with open eyes you must stare; just look down to meet my glare. To remember this ordeal, to take my ...
591 views

### Movies in movies

Each clue references a movie. Take all of the clues, combine them, and solve that clue to get you one final movie. Where did the literally animated little guy and his family come from? What type was ...
475 views

### Professor Delvershys calculations

After spending half of the night with important calculations Professor Delvershy arrived late this morning. To his dismay he discovered that one of his students used the unexpected spare time to ...
781 views

### Termite eating through a large cube composed of 27 smaller cubes while not moving diagonally

The is a large cube formed by gluing together 27 smaller cubes of uniform size (see figure). A termite starts at the center of a face of any of the outside cubes and bores a path that takes him once ...
1k views

### Careless smokers

Cosmo complains: "At the party yesterday at our place, some guys were smoking in our living room. This morning we detected that these careless smokers had burnt four holes into the carpet." Fredo: "...
438 views

### Morse of the films that I've watched a lot

After my last attempt to compile a movie list, we replaced Paul's keyboard and tried again. Once again I dictated a list of my favourite movies to Paul and he typed them up. He then gave the list to ...
1k views

### Four Letter Word

What's a four letter word that sounds exactly the same if you take away the first and last letters?
372 views

### Find the number and the trend?

I was raised this question in my PSA exam and I am still not able to find the answer.The question reads:: Find the number to replace the "???" in the given box and the trend used to find it either row-...
1k views

### In which cities do the following puns apply?

Each of the following phrases refers to a specific city on Earth. You'll find out what I mean when you get the answers. In which city... ...is there a giant blockade to prevent small rodents from ...