# 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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### Ended up with 'empathise'

I started off with a one-letter English language word. For every step, I added one letter of my choice, and re-arranged the letters to make a new word. By the end, I had: EMPATHISE What was the word ...
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### Playing Mastermind against an angel and the devil

This puzzle is based on a card game. There are 7 suspects and 3 of them committed a crime. The game contains 35 cards that contain the 35 possible choices of 3 out of the 7 suspects. One card is drawn ...
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### 27 spaces, 27 curious places

Grid 1: Grid 2: Grid 3: Find the meaning behind these images. Hint 1:
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### Justifying a redouble

This puzzle is derived from a real game of bridge I played on Bridge Base Online. I was sitting North on board 9 (N dealer, E-W vulnerable) and the bidding turned out like this: West North East South ...
• 6,996
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### Techno-Culinary Brain Teaser: Unravel the Code in the Kitchen

The answer is one word. The rebus:
1 vote
181 views

### Find the ciphering method 4

Link to the entire series. The message: ...
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### Find the ciphering method 2

Link to the entire series. The message: 3, 53, 48751, 9247757, 294914580539 The answer is a 13 letter word: UNDERSTANDING Hint 1:
265 views

### Find the ciphering method using deciphered message

Link to the entire series. Ciphered message: ...
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### Find the largest number with unique digits, that is divisible by each of its digits [duplicate]

Find the largest number with unique digits, that is divisible by each of its digits. For example 132 has unique digits and is divisible by 1, 2 and 3. But it is not the largest such number. Can you ...
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### 2 vs. 1.005^200

Without using a calculator or a computer can you determine which of these two numbers is bigger: $2$ or $1.005^{200}$ ? I saw this puzzle in a YouTube video, which I will post later.
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### Fill a 4x4 grid with minimal sum of positive integers in a way that adjacent cells contain numbers of different parity

Find a 4x4 grid containing 16 unique positive integers with minimum sum, such that adjacent numbers have different parity.
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### The Nine Gardens Of Eden

This puzzle is part of the Monthly Topic Challenge #11: Now in 3D. There are nine distinct known three-cell Garden of Eden patterns in the Life Without Death cellular automata, including the two well-...
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1 vote
264 views

### A take on custom ciphers

There is something hidden in the text below. Can you find out what it is? Note: no computers or tedious work required. ...
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### I Hate Traffic And So Do You

I need to travel through the city from my house to school, but the traffic is horrible right now. I can only move along the city's grid with the following conditions: • blocks with traffic (marked in ...
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### The minimalist game master [closed]

A game master tells his party of players that he has converted to the school of minimalism, and is going to do away with all of his dice in the campaigns they play from now on. In the place of dice, a ...
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### Puzzle "railway game set"

Alisa completes a railway game set which allows us to make various closed railway routes with crossroads. It is need to put the “rails” parts in the kit, as well as four types of “crossroads”: corner (...
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### Giraffe Necked Island

Where is this island, and why is the title of this question "Giraffe Necked Island?"
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### A different Crack the Code puzzle

This is a different Crack the Code and get the word puzzle. Here, instead of letters, actual words are hidden. The final word is a 7 letter famous person. That word consists of several words. I only ...
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### Micropoker: small hands on deck

Raise your hand if you are ready for micropoker, which minimalistically resembles 5-card poker. The deck has just 8 cards with 2 suits of 4 cards each. A hand is dealt as 3 cards that are final, with ...
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### Save now! All the digits at half the price

... or double the price depending on where you're coming from Consider the set $PD10$ of pan-digital ten-digit numbers, i.e. positive whole numbers whose decimal representation has each of the digits ...
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### Important Alien Message

A strange alien transcript, alongside what is believed to be a partial key, was recovered the other day. Scientists aren't sure what the message might contain, but theories point to some sort of ...
713 views

### Find the lower 8-digits number such that

This one come from newspapers in France, where this week is the "mathematics week", and some problems are proposed to kids. This single one is easy and funny: Find the lowest 8-digit number, ...
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### Equilibrium of differences

There is a subtraction equation written on the board, with three digits minus three digits, and the first digits both fixed. Alice and Bob need to fill in the remaining 4 digits (A~D below) using 4 ...
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### Numbers whose product of digits is a multiple of sum of digits

Find three consecutive numbers, greater than 10 and none with a digit 0 in it, each of which is such that the product of its digits is a multiple of the sum of its digits. What about four or more such ...
350 views

### How to find the value that makes this addition equation work without using a computer?

The following image represents the addition of 2 five-digit numbers, where 10 different letters represent 10 different numbers (0~9). What does PUZZLE equal? (There are two possibilities and a ...
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### Friends and Enemies

Here is a short puzzle I made: There are 10 people arranged in a row, and each of them has a friend and an enemy also present in the row. Your goal is to identify the friend and enemy of each person. ...
533 views

### What does the fox say?

I found a piece of paper on the hallway floor of my friends apartment complex, and on it is an oddly written question and an unreadable response. Can you figure this out? Question: WHAT DOES THE FOX ...
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### Trust me: you do not want to go down this road with me

Every cell has a digit from 0 to 9 or one of the four operation symbols +, −, ×, and /, signifying addition, subtraction, multiplication, and division respectively. No digit appears more than once in ...
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### Two many restrictions

Using only the number 2 several times, form the numbers 2, 22 and 222. The following operations are available: addition subtraction multiplication division exponentiation Each of these operations ...
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### What is a Nature Word™?

This puzzle is in the spirit of the What is a Word/Phrase™ series started by JLee with a special brand of Phrase™ and Word™ puzzles. If a word conforms to a special rule, I call it a Nature Word™. ...
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### What season was it?

A puzzle maker wrote this in his notebook as a holiday puzzle: Th bbie sartd unning. What season was it?
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### 125034 v1.0.0 / WR 1713-11-07

I am developing an app that generates puzzle games every day (https://125034.pages.dev/). Their basic form may be viewed as Wordle in math, Sudoku in 6 grids, or Einstein's Riddle in 1 row. If today ...
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### A logician's Bingo

Mark some cells on the following Bingo board, so that all statements in marked cells are true AND all statements in unmarked cells are false. A Bingo here is a set of five marked cells in a row, ...
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### Laziest Checkmate

Consider a game of chess where White delivers checkmate in their $X^{th}$ move. For all the pieces that remain on the board at the end of the game, consider their Manhattan Distances from their ...
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### Packing the Primes

Here is a 5x4 rectangular wordsearch (area 20) containing the primes between 1 and 100, {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} (numbers in any ...
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### How many digits does $7^{100}$ have?
I'd like to estimate $7^{100}$ without using these new-fangled computers everyone is talking about, but I think I need your help. Please estimate $7^{100}$ without the use of a computer. My friend ...