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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A City Name Game
MAIL = LIMA
ANIMAL = MANILA
PAIRS = PARIS
THEN
GOALS =
TORCHERES =
AGONISED =
ALMOST. =
AVENGE =
ANTIAR =
OARSMEN =
ASLOPE =
Please no computers and no partial answers.
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PSE Advent Calendar 2025 (Day 3): A gift from my travel agent
This puzzle is part of the Puzzling Stack Exchange Advent Calendar 2025. The accepted answer to this question will be awarded a bounty worth 100 reputation.< Previous Door Next Door >
My travel ...
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125034 v2.11 / 2025-07-11 Q1-4(v=0)
I am developing a game that generates puzzles every day (https://125034.pages.dev/). It's my opinion that these puzzles are like Einstein's Riddle in 1D.
The game and I have created four "v=0&...
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Find the missing digits in 1/2024
1/2024 is equal to $0.000\overline{a9407114b245059c88d375}$.
Can you find the values of a, b, c, and d without using a calculator?
Long division is trivial. Can you use other ways to find the missing ...
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When is the next "Factorion" date?
A "Factorion" date is a date such that when written to either one of M!+M!+D!+D!+Y!+Y!+Y!+Y! (MM/DD/YYYY), D!+D!+M!+M!+Y!+Y!+Y!+Y! (DD/MM/YYYY) , or Y!+Y!+Y!+Y!+M!+M!+D!+D! (YYYY/MM/DD) is ...
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Find a number whose divisors' factorials add up to a given number
This question did never came out in any contest.
If $\sum_{d\mid n} d!=$ ...
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Is 1,111,111,111,111 prime? Not even close!
Inspired by this question, I pose one that leans in the opposite direction.
The number 1,111,111,111,111 is not only composite. It has a factor quite small compared with what one might expect for a ...
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With the help of the cows, can you determine the secret code?
To allow new users to solve this puzzle and earn reputation points, I encourage all users whose reputation is 200 or more to not post an answer until 48 hours after this question is posted. Thank you!
...
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Show that the area of the region inside this square and regular pentagon is greater than 3/4
A square and a regular pentagon, each of area 1, are coplanar and concentric. Show that the area of the region inside both shapes is greater than 3/4.
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Cracking a coded quintic equation
They say you cannot solve most quintic equations (ones containing the fifth power of a variable) without specially designed functions. But if you can find the sequence, you can identify the positive ...
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Is 1,111,111,111,111,111,111 prime?
Now I am rereading the good old book "The Canterbury puzzles and other curious problems" by Henry Ernest Dudeney. In the introduction he presents the following illustration of puzzle ...
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How many trails from A to C?
Consider the following graph (3 edges between A,B; 3 edges between B,C; 2 edges between A,C).
How many trails are there that start from vertex A and end at vertex C? Two trails are considered the same ...
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Place a nonzero digit into some of the white cells of the grid
Place a nonzero digit into some of the white cells of the grid. Shaded cells must remain blank. No digit can repeat in a row or column. In each row, the sum of the digits must be equal to some fixed ...
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Reverse-Engineering an Incomplete Information Logic Puzzle
This is my first post to puzzling stack exchange, please let me know of any feedback you have. It's an original puzzle I made myself.
The Puzzle:
Alice and Bob are in prison for life for convincing ...
