# All Questions

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### Numbers that are the sum of the cubes of their digits

There are just four 3-digit numbers which are the sums of the cubes of their digits. For example: 370 = 3^3 + 7^3 + 0^3 and 371 = 3^3 + 7^3 + 1^3. Without using a calculator/computer, can you ...
18 views

### Multiples of their reversals

8712 and 9801 are the only 4-digit numbers which are multiples of their reversals: 8712 = 4*2178 and 9801 = 9*1089. Without using a calculator/computer, can you find two 5-digit numbers with this ...
54 views

### Can someone solve this sudoku without trial and error? Please explain

Stuck in this sudoku. If anyone can solve this then please share the method.
77 views

### Find the missing shape

Here's a grid of shapes: Which of the following shapes should go in the missing cell, and why? There is only one correct answer, and the explanation should not be very complicated.
46 views

327 views

### A functional equation again!

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: Math Excalibur Volume 22, Number 1 ...
176 views

### Mathematical golfing

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 ...
169 views

### What's the puzzle?

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 ...
140 views

### Cut It Up! (then find a phrase)

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 ...
174 views
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### Scrambler puzzle (CTF forensics problem by me!)

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 ...
59 views

### Deducing Puzzles [duplicate]

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 ...
259 views

### 120 degrees and circles

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. ...
132 views

### How to test a sudoku solver?

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 ...
382 views

### Take Two! (an Around-the-Bend)

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 ...
922 views

### Random walking on a board

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 ...
157 views

### A prolific nine-letter word

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 ...
161 views

### Hill cipher with 100x100 matrix?

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

### Defeating the deleteriousness of time

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

### My First Riddle - What am I?

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 ...
1k views

### Triply English or Triply American

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 ...
152 views

### A fairy tale in a golden toy

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. ...
330 views

### Playing the Square Chess

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 (...
428 views

### Everyone have me

Everyone have me; Without first two letters, I am not here; Without last two letters, I am a story; What am I?
6k views

### 9-5=5? Matchstick problem

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

### Complete this cross sequence

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

### Not to mean no-brainer

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 ...
179 views

### Three squares in a triangle

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 ...
240 views

### Murder on the Fairway

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 ...