All Questions

Yep, this is my 100th puzzle here in PSE~ I'm really having a wonderful time here, thank you so much guys! >< I planned to write a harder and bigger one, but it turned out I was too lazy to do that....

Find all functions $f:\mathbb{R}\to\mathbb{R}$ satisfying the following functional equation: $$f(\lfloor x\rfloor y)=f(x)\lfloor f(y)\rfloor\quad\quad\text{for all }x,y\in\mathbb{R},$$ where $\lfloor\...

Determine all functions $f:\mathbb{R}\rightarrow\mathbb{R}$ such that $$(x-2)f(y)+f\big(y+2f(x)\big)=f\big(x+yf(x)\big)$$ for all $x,y\in\mathbb{R}$. Source will be given after the problem is solved, ...

You have probably heard of code golfing? There the task is to find the shortest computer program that produces the required output. Here we want to perform math golfing - find the shortest formula ...

Someone sent me a photo of the last few lines of a puzzle. They were: BULLDOZER OVENPROOF BROADTAIL BREAKER ASYNTACTIC TIFF ALKYNE ABOUND EVASIVE BEVERAGE HILARITY COOTIE What ...

This is a "sorry for messing up yesterday's clues" puzzle. For each shape below, divide along grid-lines into identical pieces (rotation and reflection allowed). The first shape has 3 pieces, and the ...

Before anyone starts hyperventilating, this is not part of an ongoing CTF! I just made this example CTF problem for fun... To learn more about what a CTF is, check out this Wikipedia page. For this ...

There are some puzzles , where it is very difficult to find the solutions and many will probably think that there are no solutions . But actually solutions are hidden as clues in the puzzles . Here ...

The bigger circle has a radius of $1$, and it is tangent to the two straight lines that forms an angle of $120$ degrees. The smaller circle is tangent to the two straight lines and the big circle. ...

I have created a standard sudoku solver using my own algorithm. It relies on a continuous scanning with occasional tuple/pair searching. I am looking forward to test if this works properly. I have ...

Here's another around-the-bend. I felt like putting a hidden word in, but I couldn't think of anything good... there's still a word, though. Just unscramble the highlighted letters. Rules Each word ...

There’s a pawn starting in the center of this game board. At each move, it can advance randomly towards any of the adjacent squares sharing a common side with equal chance. What’s the probability of ...

For the purpose of an arithmetical puzzle I am devising, I require a nine-letter legitimate (i.e. acceptable to Scrabble players) English word such that at least one permutation of all the letters of ...

Is it possible to decrypt/encrypt something using a Hill Cipher whose key matrix has a size of $100\times100$?

What thing I'm talking about? Hint-1 Hint-2 Hint-3 Hint-4 Hint-5 (avoid)

Amber, leather, fruit, or pine. Whiskey, crackers, never wine. White and red across a sea. Or clad twice in sable, burgundy. Hidden, swung, hooked, flown. Suited, bottled, jumping, thrown. You'll ...

The following list of words divides evenly into two groups of words which I describe as Triply English and Triply American. American Assault Citation Common Count Diamond Fleet ...

Once upon a time, long long ago, in the days when good stories were far more beautiful and far harder to come by, a king was asked by his spoilt but beloved princess daughter to give her a fairy tale. ...

On an ordinary chess board (8x8) without any pieces on it as a starting position, two players will alternately place a pawn on any square (unoccupied) so that the first player that form a square (...

Everyone have me; Without first two letters, I am not here; Without last two letters, I am a story; What am I?

Move one matchstick to make an equality. Question made by me (Is this too easy?)

What is the next element of this sequence and why? Possible choices:

What does this picture mean? What are meant by different component of this picture? What is indicated by the square inside the red bevelle? Answer need to contain explanation. Ps. I made the ...

In a triangle, three identical squares of side lengths 2.8 share a common vertex and are each touching two sides of the triangle. If one of the angles in the triangle is 75 degrees and is opposed to a ...

A body has been found at the Green Estates Fairway. Next to the body was a bloody golf club which was later confirmed by the medical examiner to be the murder weapon. Thankfully, only ten men ...

I have some Raven test that I couldn't find the answers Hope you can find the answers. I found this test in this IQ Test application.

You are the principal of a primary school in HK. Schools are resuming soon, and you have to ensure that your school have enough alcohol. Each of the 30 classrooms should have a bottle containing 500mL ...

You are given an empty 10x10 grid. You are allowed to paint some of its cells as walls (black), while the remaining cells stay empty (white). A robot is programmed to start in the top-left corner of ...

Kurt, our crusty old mainframe admin, finally retired last week and I've been given the task of sorting through his files. Most of the files were comprehensible, if not understandable, like his old ~/....

The answers to the following cryptic clues all belong to a certain group. The definition part of each clue has been replaced by a number. Another number, hidden in the puzzle, gives a hint toward ...

You are given two strings A and B, each with length N. Let's index the characters in each string from 0 ― for each i ( 0 ≤ i< N), the i+1-th characters of A and B are denoted by Ai and Bi ...

I'm stumped on this puzzle! Here is a link to a Google Spreadsheets that gives you information! https://docs.google.com/spreadsheets/d/1ffxFgNtpbfhNELp8z9fv1R6Uc02BmBeR6cUG3EKXehw/edit#gid=0

Stuck with this for long time now, applied all the techniques i can think of Blank: All possibilities: missed 6 as possibility in R8C5 Verified that this has unique solution

I was pretty bored in the lockdown so I thought up a mathematics puzzle, which I haven's solved yet, so the community can solve together. Let $n>1$ be a positive integer. There is a square ...

This is a follow up to A knight chased by three knights Two players are playing a variant of chess on a 11x11 grid. The first player controls a white knight that starts in the centre square. The ...

Two players are playing a variant of chess on a 8x8 grid. The first player controls a white knight that starts in the top-left corner. The second player controls three black knights that start in the ...

Here's my second Homeworlds problem! (My first was Homeworlds: Mini Doomsday Machine.) ...

I created this puzzle. This may be really challenging. But I assure you that there is a solid logic behind. (Note: Questions are cryptic) 1: Ucbemfol.jcancyf 2: Mwamebyr;assdpwhbporcrof; File 3: ...

I went on a trip yesterday. However I can't quite remember where I went. All I have is my diary entry for yesterday, but I'm struggling to make out where it was I went still. Maybe you can help? ...

To demystify me, look and say. Then paint me not with colors but with array. ...

In a Formula 1 race, the chequered flag was waved so violently that the black and white patches got mixed up. Who was waving the flag, when and where? Other (independently solvable) puzzles of this ...

I created this puzzle. Find the message. q螣 s䈚 q蟝 v쀎 q蟾 q蠸 q襪 q褰 q弧 q螣 q襪 q蛡 q袈 q蟝 Hint 1: Hint 2: My other puzzles can be found here.

Grid in plaintext Across 1/13/20. State of Colorado engaged in attempt to pursue mostly American parties, often involving heroin (10,8,2,3,5) 10. "Terminal engineer, too, must… (7) 11. …ultimately ...

I went back in an old Flash game and was intrigued by this problem. Rules There is an $n\times n$ grid and a mouse entering on the entrance cell and exiting on the exit cell. The entrance ...

This is a puzzle posted on a social networking site that I have been trying hard since yesterday to solve: My approach has been to find out a mathematical function with the numbers in the yellow, ...

This puzzle is based on Creating the hardest 6x6 maze You are given an empty 7x7 grid. You are allowed to paint some of its cells as walls (black), while the remaining cells stay empty (white). A ...

The answer to this puzzle is a list of ten thematically related words or proper names or phrases. Each of these is clued cryptically, and the theme is to be determined. Since the definition part of a ...

This puzzle is part of the openly available questions from a book. I'm trying to solve it, but cannot find any solution to it. The book inside preview says the answer is top right one (two solid ...

Each of the letters of the word EDUCATION is assigned a different integer value between 1 and 9, for a total value for the word of 45. With the same value for each of the letters, the total values of ...

This is in the spirit of the What is a Word/Phrase™ series started by JLee with a special brand of Phrase™ and Word™ puzzles. If a word adheres to a certain rule I call it a 21 + 3113 Word™. Text-...