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Questions tagged [no-computers]

A puzzle designed to be solved without using calculators, online decoders, or computer programming. Using a computer to type and post the answer is allowed; the spirit of this tag is to make people solve the puzzle on their own.

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12 votes
1 answer
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Follow the path of relation through the grid #1

There is a relation between rectilinear-adjacent squares such that there is a unique rectilinear path from the top-left corner of the grid down to the bottom-right corner of the grid. Each square can ...
Galen's user avatar
  • 2,296
7 votes
1 answer
275 views

Follow the path of relation through the grid #2

There is a relation between rectilinear-adjacent squares such that there is a unique rectilinear path from the top-left corner of the grid down to the bottom-right corner of the grid. Each square can ...
Galen's user avatar
  • 2,296
6 votes
1 answer
224 views

Follow the path of relation through the grid #3

There is a relation between rectilinear-adjacent squares such that there is a unique rectilinear path from the top-left corner of the grid down to the bottom-right corner of the grid. Each square can ...
Galen's user avatar
  • 2,296
12 votes
2 answers
506 views

Wormeus and the Pink Lady Stickotaur

Wormeus lives in a labyrinth containing lots of apples. His main ambition in life is to eat as many apples as possible but his nemesis, the evil Pink Lady Stickotaur, has other ideas – if you pardon ...
happystar's user avatar
  • 7,664
3 votes
1 answer
167 views

Follow the path of relation through the grid #4

There is a relation between rectilinear-adjacent squares such that there is a unique rectilinear path from the top-left corner of the grid down to the bottom-right corner of the grid. Each square can ...
Galen's user avatar
  • 2,296
20 votes
5 answers
1k views

Square Spin #1: Sun and Moon

Defining Square Spin Lets play a game! The aim of this game is to transform one image into another using the least amount of moves possible. Here is what a move consists of: ...
Adam's user avatar
  • 2,907
15 votes
2 answers
390 views

Barrel - Part 5

An entry in Fortnightly Topic Challenge #35: Restricted Title 1. Title based on this xkcd. This is a continuation of Barrel - Part 1, Barrel - Part 2, Barrel - Part 3, and Barrel - Part 4, but this ...
Riley's user avatar
  • 14.5k
5 votes
2 answers
237 views

Follow the path of relation through the grid #5

There is a relation between rectilinear-adjacent squares such that there is a unique rectilinear path from the top-left corner of the grid down to the bottom-right corner of the grid. Each square can ...
Galen's user avatar
  • 2,296
37 votes
1 answer
2k views

Riley Riddles in Reverse

In the all-famous Riley riddles, you have to guess one word from clues about its prefix, infix and suffix. Here, instead, You get three words. You must find one solution word that you can attach.....
Bass's user avatar
  • 77.7k
34 votes
4 answers
8k views

First digit of 3^2020

Inspired by The last digit for 3^(2019) Can you find the first digit of 32020 without a computer?
Dmitry Kamenetsky's user avatar
22 votes
7 answers
4k views

What number is that ? Asks Grandpa

"So here is a number between 1 and 60" Says Grandpa "If you take its WORD anagram and subtract this number you will get Anagram of the number - number > 5 What is that number"? "So it is the ...
DrD's user avatar
  • 39.4k
18 votes
2 answers
899 views

Color Logic - Find the rule

Find the rule specified in the image below. (Where I got it)
u-ndefined's user avatar
  • 5,181
15 votes
3 answers
420 views

Some-what-not-with-standing word connections

What words can fill the boxes?   Each pair of linked words forms an uncapitalized unhyphenated word when joined end-to-start according to their left-to-right or top-to-bottom order in the link. ...
humn's user avatar
  • 21.9k
14 votes
2 answers
874 views

PSE Advent Calendar 2021 (Day 4): Decorating with Ingrid Deduction

This puzzle is part of the Puzzling StackExchange Advent Calendar 2021. The accepted answer to this question will be awarded a bounty worth 50 reputation. < Previous Door Next Door > "...
Jeremy Dover's user avatar
  • 28.5k
14 votes
2 answers
940 views

Some Stratospherically Strenuous Sudoku

These three sudoku are particularly irksome, can you logically deduce the solutions to all (or any!) ...and provide your reasoning? They are all proper sudoku - each has a unique solution. They can, ...
Jonathan Allan's user avatar
12 votes
2 answers
2k views

Alphabetical Sudoku

Who loves fish? Okay that might sound a bit weird but don't worry, I am still sane. Maybe. To answer the question you must complete the Sudoku below. A word will appear in the highlighted box which ...
Beastly Gerbil's user avatar
11 votes
2 answers
861 views

What is the probability that all the bullets will be destroyed?

A gun shots bullets with different speed each second. The bullets form a straight line. The bullets keep their speed (not getting slower or faster). But if 2 of the bullets collide, 2 of them are ...
Jamal Senjaya's user avatar
7 votes
2 answers
448 views

Square Spin #2: Climb the Mountain!

Square Spin History: #1>#2 New Rules This puzzle introduces two new square types: Unmovable squares (Un) Replaceable squares (Re) Plus the concept of ambiguity! Ambiguity of squares Certain ...
Adam's user avatar
  • 2,907
7 votes
2 answers
362 views

Desert Wanderings bring…Ciphers? Part 2

Part 1 can be found here Part 3 can be found here As you utter your answer, along with its reasoning of course, the Sphinx clearly looks disappointed. You are unfortunately… Correct. Clearly I made ...
dcfyj's user avatar
  • 7,756
5 votes
1 answer
154 views

Follow the path of relation through the grid #6

There is a relation between rectilinear-adjacent squares such that there is a unique rectilinear path from the top-left corner of the grid down to the bottom-right corner of the grid. Each square can ...
Galen's user avatar
  • 2,296
68 votes
2 answers
5k views

Sudoku like you've never seen it before

I've spent this week trying to create a difficult logic puzzle which is a combination of two Sudoku varaints, 'Samuari Sudokus' and 'Pseudokus', and this combo is unlike anything you can find online. ...
Beastly Gerbil's user avatar
32 votes
5 answers
5k views

How can 3 queens control the white squares?

It is well known that there is no way of arranging 4 queens on a checker board in such a way that every square is occupied or threatened. Now consider a slight variation where we only need to cover ...
Paul Panzer's user avatar
  • 10.3k
30 votes
1 answer
876 views

PSE Advent Calendar 2021 (Day 20): Candy Cane Sudoku

This puzzle is part of the Puzzling Stack Exchange Advent Calendar 2021. The accepted answer to this question will be awarded a bounty worth 50 reputation.< Previous Door Next Door > So I was ...
Jeremy Dover's user avatar
  • 28.5k
19 votes
2 answers
1k views

Self-intro to mo-Roman numerals

Here come mo -Roman numerals — just like Roman numerals, only mo’ so.   (Explained as we go.)   What number can spell itself in two different ways ...
humn's user avatar
  • 21.9k
18 votes
7 answers
2k views

Fully-Firstable Anagram Sets

Okay, first let's define some terminology: Anagram - Oh come on, how are you on Puzzling.SE if you don't know this one? Anagram Set - a list of words that are all anagrams of eachother, e.g.: ACTS ...
Darrel Hoffman's user avatar
18 votes
2 answers
782 views

PSE Advent Calendar 2023 (Day 9): The Peppermint Twist

This puzzle is part of the Puzzling Stack Exchange Advent Calendar 2023. The accepted answer to this question will be awarded a bounty worth 50 reputation.< Previous Door Next Door > This puzzle ...
Jeremy Dover's user avatar
  • 28.5k
18 votes
4 answers
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. + ...
DrD's user avatar
  • 39.4k
17 votes
9 answers
5k views

Solitaire Chess

A friend of mine got me Solitaire Chess for Christmas years ago. I set up the board below. Is it possible to solve it? If so, what is the solution? (No programs allowed- Use only your brain.) Rules: ...
JLee's user avatar
  • 19.4k
14 votes
9 answers
4k views

Perfect Squares!

A question was asked in a mental ability test yesterday. Write four distinct numbers with these properties: 1. Sum of each pair is a perfect square. 2. Sum of all four is also a perfect ...
ABcDexter's user avatar
  • 7,262
14 votes
3 answers
1k views

Crossword gone overboard

This puzzle is part 24 of Gladys' journey across the globe. Each part can be solved independently. Nevertheless, if you are new to the series, feel free to start at the beginning: Introducing Gladys. ...
Jafe's user avatar
  • 78.1k
14 votes
3 answers
1k views

If 6 was 9, or 100 was 64, or M was N

         Now if a 6,          Turned out to be 9,          I don’&...
humn's user avatar
  • 21.9k
11 votes
2 answers
4k views

How many Strobogrammatic numbers are there from 0 to 99999

0,1,2,5,8,11,69,96 are Strobogrammatic numbers. We call a Strobogrammatic numbers if: When it is typed on a calculator, and the calculator is spun 180 degrees, the number visually looks the ...
Jamal Senjaya's user avatar
11 votes
2 answers
8k views

Find the 4-digit code!

An agent has created a 4 digit code from the result of a maths equation involving all the digits 1-9. We know where the number 3 appears in the multiplication, but not any of the other 8 digits. <...
Nick D's user avatar
  • 113
10 votes
2 answers
341 views

How to fill a honeymoon

        How can a honeybee visit all cells exactly once in this crescent shaped honeycomb, beginning at the bottom tip and ending at the top? The starting cell, at ...
humn's user avatar
  • 21.9k
9 votes
1 answer
205 views

Wormeus and the Stickotaur (maze 2)

Here is another Wormeus maze, following a previous puzzle that is yet to go viral. Wormeus has to eat all the apples without dying a horrible squishy death at the hands of the Pink Lady Stickotaur. I ...
happystar's user avatar
  • 7,664
9 votes
1 answer
337 views

Simple Homeworlds puzzle

On this site, we have numerous chess puzzles. however, we do not seem to have any Homeworlds puzzles, the game of space kings (yes this can be tagged outer space thank you very much.) Hence, here is ...
Destructible Lemon's user avatar
9 votes
2 answers
352 views

Word connection squares!

This puzzle is in the spirit of Word connections, but is a more elaborate version of the same idea. In each puzzle, you have a square of seven words of the following form: ...
Rand al'Thor's user avatar
7 votes
1 answer
2k views

Encoding Morse Code

The letters of a message are converted to Morse code, with a space between each pair of letters and two spaces between each pair of words. Each pair of elements (for example dot-space, dash-dash, and ...
noneuclideanisms's user avatar
7 votes
2 answers
966 views

Triangle with incircle [closed]

This question is from the German mathematics competition Känguru der Mathematik. In this competition students have to solve 30 mathematical tasks like this in 90 minutes without calculator. Actually ...
A. P.'s user avatar
  • 5,948
4 votes
4 answers
439 views

Word connections

I am trying a new kind of puzzle so feel free to leave constructive comments and opinions! Thank you! The objective of this puzzle is to connect 2 words by using a chain of words that connects each ...
stack reader's user avatar
  • 9,840
4 votes
1 answer
215 views

Follow the path of relation through the grid #7

There is a relation between rectilinear-adjacent squares such that there is a unique rectilinear path from the top-left corner of the grid down to the bottom-right corner of the grid. Each square can ...
Galen's user avatar
  • 2,296
3 votes
1 answer
158 views

Follow the path of relation through the grid #8

There is a relation between rectilinear-adjacent squares such that there is a unique rectilinear path from the top-left corner of the grid down to the bottom-right corner of the grid. Each square can ...
Galen's user avatar
  • 2,296
2 votes
2 answers
136 views

Tiling rectangles with Hexomino plus rectangle #2

Inspired by Polyomino T hexomino and rectangle packing into rectangle See also series Tiling rectangles with F pentomino plus rectangles and Tiling rectangles with Hexomino plus rectangle #1 ...
theonetruepath's user avatar
1 vote
2 answers
265 views

Tiling rectangles with Heptomino plus rectangle #7

Inspired by Polyomino T hexomino and rectangle packing into rectangle See also series Tiling rectangles with F pentomino plus rectangles and Tiling rectangles with Hexomino plus rectangle #1 ...
theonetruepath's user avatar
54 votes
1 answer
2k views

re-re-reCAPTCHA

Last Friday, I was feeling a bit sad because I hadn't earned much rep recently, so I decided to try this awesome sock puppet thing everyone's been raving about. I logged out of my normal Puzzling ...
Dan Russell's user avatar
54 votes
3 answers
3k views

A 16 Clue Sudoku Puzzle (but the kings can't be in check)

An entry in the 19th fortnightly challenge... Above is a 9x9 "chess" board with some pieces already laid out, your goal is to fill the board completely, following standard Sudoku rules (i.e. every ...
Alconja's user avatar
  • 37.3k
50 votes
4 answers
3k views

Five Slitherlinks

Solve five Slitherlinks, each with a unique solution. Please say a word regarding (or show an image depicting) each solution method.
DyingIsFun's user avatar
  • 9,186
49 votes
2 answers
4k views

Can you stop the rambling rook?

This is a chess puzzle someone showed me a long time ago. If you already know this puzzle please give the others a chance to solve it first. This puzzle was originally created by Otto Gallischek and ...
Sleafar's user avatar
  • 18.1k
46 votes
2 answers
3k views

A simple nonogram

Solve the nonogram.                   (Click for a larger version.)
DyingIsFun's user avatar
  • 9,186
41 votes
5 answers
7k views

Unusual letter combinations

This is an entry in the Fortnightly Topic Challenge #41: Short and Sweet. English spelling is very strange. Sometimes you encounter words with letter combinations that would seem entirely ...
GentlePurpleRain's user avatar