Questions tagged [no-computers]

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

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7
votes
1answer
232 views

The Newest Cycle

A wonderful new chess problem has appeared lately that is most wonderful. I am here to share it with the world today. But you must solve it in order know about it’s glory! It’s White to move and ...
17
votes
3answers
3k views

Prime to Prime: Get all first 25 Prime Numbers using up to 4 Primes

The first 25 Prime Numbers are 2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,89,97 Using up to 4 prime numbers and the following mathematical operations, get all the 25 primes. ...
10
votes
1answer
393 views

Twelve Labours - #12 Pluto Pups

This puzzle is part of the ‘Twelve Labours’ series, but can be solved independently. Previous instalments can be found here: Prologue | 01 | 02 | 03 | 04 | 05 | 06 | 07 | 08 | 09 | 10 | 11 It was ...
3
votes
1answer
152 views

Rotary phone with numbers and letters

I am going to organise a quest for teenagers. I have a vintage phone like below: I am looking for ideas how to use the rotary phone with numbers 1,2, ..., 9, 0 and letters A, B, C, F, H, I, K, L, M, ...
8
votes
1answer
681 views

(Im)Possible 8-Puzzle

Can you solve this 8-puzzle in 16 moves or less?
12
votes
2answers
761 views

Hearts and Spades in a Row

From a deck of playing cards remove hearts ace to seven, and spades ace to seven. Now place them on a table in a row so that the number of cards between the two aces is 1, the number of cards ...
3
votes
2answers
312 views

What was Grandpa really doing?

"Guess what happened during my walk". Said Grandpa "I saw gods in a ghetto"! He continued with a smile. "What?" I said. "Well, not really. But can you guess what I did?", Grandpa asked. ...
4
votes
1answer
91 views

You Tell Me What To Choose

I found this nice problem in A.C. White’s 1912 book “The Theory Of Pawn Promotion” the other day. Enjoy! It’s White to move and checkmate Black in 5 moves, Don’t forget to explain the title! ...
2
votes
4answers
607 views

Grid Puzzle - Paint

A student was found making Graffiti in the teacher's office. He was punished and was asked to repaint the wall of the room. The teacher gave him a grid to show which part of the wall should be painted ...
10
votes
4answers
2k views

What's the most rewarding path?

Get from the top-left to the bottom-right using only right and down moves. Pick up as much gold as possible. There is only one maximum.
3
votes
2answers
194 views

Minesweeper puzzle - Too many twos

A Gobo is caught for leaving the school for the lnternet bar to play computer games without permission. He is asked to solve a problem. Put 4 mines in a 3 by 5 minesweeper grid to fill ALL the other ...
8
votes
2answers
254 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
289 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
159 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. Gijs van Breukelen, Schakend Nederland, 1981, Special Honoring ...
17
votes
1answer
939 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. ...
6
votes
1answer
97 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
70 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
128 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
205 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
172 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. David Gurgenidze & ...
13
votes
1answer
868 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
667 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 ...
11
votes
2answers
222 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
328 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.
11
votes
1answer
291 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
150 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
493 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
154 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 ...
20
votes
1answer
715 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
548 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
970 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
213 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
168 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! *Oleg Pervakov and Karen Sumbatian, Shakmaty v ...
-1
votes
1answer
51 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
94 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 ...
9
votes
3answers
418 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. No looking up the solution please! Nikita M. Plaksinm ...
4
votes
2answers
197 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
457 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
156 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 ...
8
votes
2answers
1k 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
260 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
105 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
1answer
542 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
181 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
333 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
200 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. Миљанић, ...
3
votes
2answers
241 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: ...