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Questions tagged [no-computers]

A puzzle designed to be solved without using calculators, online decoders or computer programming.

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8
votes
2answers
230 views

Hand tiling puzzle demonstrating Eisenstein triple $c^2 = a^2 -ab + b^2$

An Eisenstein triple is related to 60 degree triangles and a special case of the cosine law. But we need not worry about that except to note that a specific example of an Eisenstein triple is $7^2 = 5^...
10
votes
3answers
284 views

Four hand tiled squares demonstrating a Pythagorean Quadruple

Demonstrating the Pythagorean Quadruple $6\times6 + 6\times6 + 7\times7 = 11\times11$ Using the pieces shown in the $11\times11$ square: The objective: Arrange the pink pieces (four enneominoes) ...
4
votes
0answers
135 views

The Rambling Monster

The Rambling Rook is back, but this time, they are a true monster! It’s White to move and reach a winning position in 101 moves. Source: Gijs van Breukelen, Schakend Nederland, 1981, Special ...
17
votes
1answer
932 views

Son of the Revenge of the Riley Riddles in Reverse Strikes Again

Because why not, here's yet another bunch of these inverted riddles, where the solutions are what you'd usually use as the wordplay clues in a Riley Riddle. Here's how it goes: You get three words. ...
5
votes
1answer
86 views

A Curve of Pursuit Yajilin

Following on from my previous Yajilin, I wanted to make a harder one for your entertainment and amusement, and hopefully to keep @Deusovi occupied for more than 20 minutes. Rules (shamelessly ...
0
votes
1answer
67 views

TripTog's problem with his socks [closed]

Our friendly three-footed alien TripTog has two triplets of socks, which he keeps in a drawer in a room. Each triplet of socks is labeled 1, 2 or 3, because TripTog is very meticulous about which ...
4
votes
1answer
116 views

“Short” And Sweet Math

In the following chess diagram, how many possible chess postions exist? No looking at the solution! Source: P1359129 & Andrew Jonathan Mestel, Retros mailing list, 2/1/2019
6
votes
5answers
191 views

Chess Construction Challenge #3-The Inverse Babson

Another day, another task! Today's challenge is to construct four positions, with White to move and win, such that: In each position, White's move is to promote to a particular piece, for a position ...
7
votes
4answers
2k views

Smallest number containing the first 11 primes as sub-strings

113257 contains the first 6 primes as sub-strings when reading them from left to right: 2: 113257 3: 113257 5: 113257 7: 113257 11: 113257 13: 113257 What is the smallest number that contains ...
3
votes
2answers
155 views

Back in time, in my time, all the time

I present to you all a highly interesting problem that I came across awhile ago on Tim Krabbe’s site. It’s White move and win, i.e. reach a winning positon, in 21 moves. Source: David Gurgenidze &...
13
votes
1answer
857 views

Dear Fellow PSE Users,

This puzzle is dedicated to all of you! Instructions There are 8 anagram questions below. In each question, you can rearrange the letters to find an answer, which is 2 English words that describe a ...
10
votes
2answers
657 views

The Google Earth Challenge: “A dangerous flower”

This puzzle is based on Where is it? - The Google Earth Challenge series started by Conifers This puzzle will provide a screenshot in somewhere on Google Earth, please try your best to identify where ...
12
votes
2answers
196 views

Missing lattes and mutually mistrustful words

It's always amusing to watch two kids who don't trust each other swap baseball cards by exchanging them at exactly the same moment. Words can be equally mistrustful about trading their letters. ...
7
votes
2answers
312 views

Not Seven This Time - another Google Earth challenge

Where is this? Please don't use Google reverse image search, but solve the puzzle using inspiration and deduction.
12
votes
1answer
247 views

Don't look back, crazy clown

Start with these two words INSANE RETROSPECT and see if you can get them to exchange places by transferring one letter at a time. With each ...
7
votes
1answer
145 views

Manually mixing words

Inspired by my struggles with this puzzle. In that puzzle, I needed to mix two words, meaning blend them together without changing the order. For example, "ab" mixed with "cd" would give us 6 new ...
9
votes
1answer
469 views

Connect the wires without setting off the bomb

You just saw a planted time bomb! Just 5 minutes are remaining until it explodes and as you are in currently in a rural area (no bomb disposal squad) and you know how bombs usually work it is up to ...
4
votes
1answer
151 views

A Remote Location

Here be a simple problem For the keen directmate eye White to move and win In seven moves, Black shall die However, I remember now a relative Long ago did he begin to live About a two decades or ...
21
votes
1answer
695 views

The little bee buzzes around the flower garden

Watch the little bee buzz around the flower garden. Pay particular attention to how he picks up or drops off pollen (i.e., a single letter) at each flower. Notice: — The little bee visits each ...
8
votes
1answer
546 views

Winning the Lottery

Bob: I hear you won the lottery. Alice: So I did! Bob: What six numbers did you win it with? Alice: Can't remember. All I recall is that they were all different, and none greater than 28. Bob: ...
14
votes
2answers
965 views

The 7-numbers crossword

This crossword doesn't have any regular clues, however, all the words are made with the same 7 letters (each of them got a number). No automatic solvers are allowed. CSV version: ...
7
votes
1answer
202 views

A Game of Sprouts

I have a partially played game of sprouts that I need help solving. The rules are simple (Kevin over at VSauce2 did a great job explaining it if you don't like reading, though the Yoda voice is a bit ...
2
votes
0answers
150 views

Around The World

It's White to move and checkmate Black in 36 moves. I have slightly changed the original stipulation. Feel free to explain the title if you want to! Source(Couldn't copy and paste!): (Oleg Pervakov ...
-1
votes
1answer
50 views

lightest ball among 8 balls by 2 tries using a balance scales [duplicate]

I have 8 balls and one of them is lighter than others. How could I find that ball by 2 tries? Also I have a balance scales.
3
votes
1answer
88 views

Alphametic puzzle, involving square and prime numbers [closed]

I have been trying puzzle solving recently and came across this problem. Any hints on how to do this? So far, I have found that N, R and F must be odd (as they are the last digit in a 5 digit prime ...
8
votes
3answers
385 views

So, what's to do?

It's White to move and draw the game. What must White do? You must provide proof for your claim of what's to be done by any reasonable means. This puzzle was created by Nikita M. Plaksin, and ...
4
votes
2answers
192 views

The Dropper, But With A Twist

Here's a piece-drop puzzle of my own. In the below position, a White piece is to be dropped onto the board. This means that, before White can move, they must legally put a single piece on them board. ...
10
votes
1answer
443 views

100 Years of GCHQ - A quick afternoon puzzle!

I'm off to the Science Museum London tomorrow, to the Exhibition celebrating 100 years of GCHQ. As such, they sent me a little reminder email this afternoon. On the bottom of the email was the ...
2
votes
1answer
151 views

That Ain't Right… #4

Here's a small head-scratcher for you all today. In the above position, it is White to play and mate Black in four moves, assuming that Black plays their best moves. However, there is a catch—there ...
6
votes
1answer
952 views

Dodgy Dies: The Puzzling Premiere

Inspired by the "Treasure Hunter Monolith" minigame from Danganronpa V3 Dodgy Dies Guide Terminology Block - a single die on the grid. Cycle - a list of blocks Value - the ...
5
votes
2answers
243 views

Tempoverlustspiel

Tempoverlustspiel-A German word that roughly translates to "loss of tempo game." An interesting chess term that I leaned a while ago With White to move in the below position, how many moves will it ...
3
votes
1answer
103 views

A Breeze Through

Here's a small problem for you all to breeze through tonight! It's White to move and selfmate themselves in 7 turns. Can you tell me what the special concept is that arises from this problem? As ...
7
votes
2answers
525 views

Don't bully your little sister at chess

This puzzle was inspired by @RewanDemontay's puzzle De-zephyr The Solution!. Rewan kindly granted me permission for making this puzzle and citing his as my source of inspiration. I thought of naming ...
6
votes
1answer
175 views

De-zephyr The Solution!

Here's another original chess problem of mine for you all to solve today! In the following position, White wants to stalemate Black even though they can win, for unknown, unclear, unexplained, and ...
0
votes
1answer
102 views

coordinate encription

today I found myself in front of the following codified text: MzIgVCA2NTg3MjYgNDg1MTY0Nw0KMzIgVCA2NTc5OTkgNDg1MzExMw0KMzIgVCA2NTc0MDUgNDg1MjMxM ...
15
votes
1answer
329 views

Newton's cradles

I went to one of those discovery stores and picked up a few Newton's cradles, except these have hanging words instead of hanging spheres. Check it out: This one has a starter pendulum with two ...
2
votes
1answer
179 views

The Sea Snake's Slithering Problem

Here's a really long chess puzzle, not made by me, that has the "sea snake" theme, which just basically means that it's super long. It's White to move and checkmate Black in 122 moves. Please do not ...
3
votes
2answers
231 views

Coin around shapes: A Geometric paradox?

Here is a circular coin with diameter D Figure A From its starting position the small coin goes completely around a bigger circular body of diameter 4D without slipping, always in contact ...
20
votes
1answer
1k views

Farmer needs to get his word across the river

In the spirit of the classic river-crossing puzzles: ...
8
votes
2answers
328 views

Square Spin #4: Rude Awakening

Square Spin History: #1>#2>#3>#4 New Rule This puzzle introduces a new square type: Lonely squares (Ly) Lonely squares This type of square contains a box and it is ...
4
votes
2answers
196 views

Chess Construction Challenge #1-Read First Please!

I'm starting a new series in which I set a very specific goal with a unique (to be more specifically defined here in a bit) answer in which the solver must construct a chess position, sometimes a game,...
2
votes
1answer
134 views

Oops! Mixed up Multiplication - Needs to be Fixed

$Given$: $U$, $V$, $C$ are distinct digits, varying from 1 to 9. $U$ > $V$ > $C$ $UVC$, $VCU$, $CUV$ are concatenated Numbers $(UVC)*(VCU)*(CUV)$ = $234235286$ The digits on the right hand side ...
1
vote
5answers
259 views

How fast can you “DOCK” the “SHIP”? [closed]

You have to reach DOCK from SHIP in the minimum number of tries with the following rules. You are only allowed to change one letter at a time. You have to keep the word length the same. At each step ...
5
votes
1answer
209 views

Square Spin #3: Hickory Dickory Dock

Square Spin History: #1>#2>#3 Recap of the Rules Basic rules from #1 Ambiguity, Un and Re squares from #2 Problem #3: Hickory Dickory Dock The mouse ran up the clock. ...but ...
2
votes
1answer
118 views

What is the Last Digit in the Result of the given Expression? [closed]

$Given$: $ASC$ is a concatenated number with distinct digits. $S$ is square of $A$, $C$ is cube of $A$ Deduce the last digit of the following Expression through Deductive Reasoning only: $$\begin{...
1
vote
1answer
54 views

Pan Digital Split among Two Powers

$Given$: $AB$, $DBCE$,$AGFPQR$ are three concatenated numbers with all distinct digits varying from zero to nine. $AB^C$ = $DBCE$ $AB^F$ = $AGFPQR$ Deduce all the digits through logical reasoning ...
-4
votes
4answers
161 views

Go for the Gold

You are given a bag containing 1 and 2 ounce gold rounds. You need to draw one coin at a time till they Sum up to ten rounds. How many different ways you can achieve that? What is the quickest path ...
1
vote
1answer
90 views

Express the given Fractions as Continued Fractions

Using only the numbers, $1$, $2$, $12$. No concatenations allowed. Only permitted signs are plus and division. Brackets are not needed. Expressions should be as concise as possible. Typical ...
8
votes
1answer
278 views

3D Chess - Stale NBA (kNight-Bishop Assault)

This is my very first chess puzzle. Any constructive feedback is more than welcome. Thanks! Introducing 3D Chess! To make things simple for the first time, we are using a $3\times3\times3$ ...
3
votes
1answer
192 views

Holy Alphabet Arithmetic

$Given$: $A$+$B$+$C$=3 $B$+$C$+$D$=3 $C$+$D$+$E$=1 $D$+$E$+$F$=1 What is $E$+$F$+$G$=?