Questions tagged [no-computers]
A puzzle designed to be solved without using calculators, online decoders or computer programming. You're still allowed to use a computer to post the solution; Stack Exchange doesn't support smoke signals yet.
108
questions
13
votes
1answer
315 views
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 ...
7
votes
1answer
231 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 ...
6
votes
1answer
199 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 ...
20
votes
5answers
835 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:
...
14
votes
2answers
340 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 ...
35
votes
3answers
6k 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?
13
votes
3answers
835 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, ...
18
votes
2answers
846 views
37
votes
1answer
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.....
22
votes
7answers
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 ...
12
votes
2answers
1k 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 ...
15
votes
3answers
369 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.
...
7
votes
2answers
328 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 ...
7
votes
2answers
332 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 ...
5
votes
2answers
223 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 ...
17
votes
9answers
4k 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:
...
14
votes
9answers
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 ...
10
votes
2answers
7k 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.
<...
18
votes
7answers
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
...
14
votes
3answers
1k views
6
votes
1answer
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 ...
19
votes
2answers
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
...
16
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.
+ ...
14
votes
3answers
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.
...
10
votes
2answers
318 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 ...
7
votes
2answers
925 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 ...
10
votes
2answers
3k 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 ...
9
votes
2answers
282 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:
...
9
votes
1answer
285 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 ...
5
votes
1answer
139 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 ...
4
votes
4answers
394 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 ...
3
votes
1answer
148 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 ...
2
votes
2answers
104 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
...
1
vote
2answers
172 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
...
60
votes
2answers
3k 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. ...
30
votes
1answer
2k views
A Secret Job . . . but what is it?
Mr. Peters, a freelance muscle-for-hire sort of fellow, had been manning his desk for days now waiting for something to do when at last the phone rang. A job! The nerdy sounding person on the other ...
51
votes
1answer
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 ...
48
votes
2answers
3k 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 ...
43
votes
2answers
2k views
24
votes
5answers
2k views
Superhero words!
Quietly walking among us are words which are actually superheroes in disguise! Just as Diana Prince spins around to become Wonder Woman, some seemingly ordinary words can spin around to reveal their ...
51
votes
2answers
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 ...
29
votes
3answers
3k views
Uh oh, the propeller fell off
I was rummaging through a trunk in the attic when I found this vintage game. It is some sort of pinwheel or propeller mounted on a board. The propeller has a cryptic series of letters painted on it, ...
16
votes
1answer
581 views
Riley Riddles in Reverse, batch 2
"post some more sometime :)" -- user @Dragonrage in the comments of Riley Riddles in Reverse
Here's another batch of "inverted" Riley riddles. These still work exactly like the ones before:
You ...
43
votes
4answers
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.
31
votes
1answer
2k views
Computation without a computer
In the number $(1+\sqrt{3})^{2015}$, what is the 224th digit after the decimal point?
You may NOT use a calculator, computer, or any electronic aid to answer this question. Only pen(cil), paper, and ...
20
votes
2answers
1k views
Sudoku in the third dimension (3D Sudoku)
People seemed to enjoy my last Sudoku variant puzzle - Samurai Pseudoku, so I spent this week making another! This one is going to require using logic you've never used before...
The last one was a ...
17
votes
1answer
1k views
The Lord of the Puzzles
In 1904 (at the age of 12) J.R.R. Tolkien sent a "puzzle letter" (pictured below) to a family friend; Father Francis Morgan.
What does it say?
Obviously it would be trivially simple to google the ...
8
votes
1answer
384 views
Whose birthday is it?
A group of people have gathered for a birthday celebration. Their ages are related as follows:
The product of the 1st person's and the 2nd person's ages is $311\frac{2}{3}$ plus the 3rd person's age.
...
30
votes
2answers
2k views
Parallelisation
An entry in Fortnightly Topic Challenge #32: Grid Deduction Hybrids
Puzzlers, I am presenting a set of six duo-grids! Of course, I need to tell you how they work - you are given a grid. Looking at it,...
20
votes
1answer
1k views
Farmer needs to get his word across the river
In the spirit of the classic river-crossing puzzles:
...
