Questions tagged [no-computers]

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

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8
votes
1answer
263 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 ...
8
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1answer
169 views

Uh oh, now the boards are missing!

I found another trunk in the attic, with more of those vintage propeller games. This time, I've got propellers, but no boards. Is it possible to figure out the whole board from just the propeller? ...
8
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3answers
1k views

Let's go back in time!

Okay, so below are a handful of ciphers. They're pretty easy to identify, ranging from simple substitution to complicated binary. Some may have the keyword given others you have to solve. Now you're ...
8
votes
3answers
211 views

Hand tiling puzzle

Here's a set of polyominoes (sizes 4,5,6,7,8,9,10) that you can print and cut out. You can use the two smallest to make a 3x3. Nice easy one to get you started. Add a piece to make a 3x5. Add another ...
8
votes
1answer
694 views

(Im)Possible 8-Puzzle

Can you solve this 8-puzzle in 16 moves or less?
8
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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 ...
8
votes
1answer
132 views

Products or sums

Arrange the integers between 1 to 20 on twenty of the cells of this board, precisely two on each row and each column. The sum or product of the two numbers in each row must be the number on its right, ...
8
votes
1answer
557 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: ...
8
votes
2answers
392 views

Minimum number of tries to find the balance!

There are 8 distinct weights and a two-pan equal arm balance scale, and you know the weights' weight order: the lightest is numbered as 1 and the heaviest is numbered as 8 and the rest accordingly. ...
8
votes
1answer
287 views

3D Chess - Stale NBA (kNight-Bishop Assault)

This is my very first chess puzzle. Any constructive feedback is more than welcome. Thanks! Introducing 3D Chess! To make things simple for the first time, we are using a $3\times3\times3$ ...
7
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2answers
728 views

Evaluate the nested square roots

Evaluate the following expression to 4 decimal places: $$\sqrt{1+2\sqrt{1+2\sqrt{1+\dots+2\sqrt{1+2\sqrt{2015}}}}}$$ where the number of square roots in the expression is exactly 2015. As per the ...
7
votes
4answers
1k views

Comparing exponents - no computers!

Which is larger, $99^{100}$ or $100^{99}$? Which is larger, $999^{1000}$ or $1000^{999}$? Or more generally, for $n$ any natural number: which is larger, $n^{n+1}$ or $(n+1)^n$? Please do not use a ...
7
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3answers
960 views

A bad and boring riddle, and an easy alphametic

First comes the bad and boring riddle (the answer is to be written in all capital letters): Magnesium plus Gallium yields a joke. Next comes the easy alphametic: Solve the answer to the bad ...
7
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3answers
742 views

No spanish required

Each letter represents a digit, so what is Mucho and Poco (although who's to say?) ...
7
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2answers
737 views

Last contact in custody

You came so close. The job was going so well. You just never expected that the police would have a surveillance cat. That's what you get for trying to steal things in an age where people are ...
7
votes
3answers
399 views

A colorful wheel

Here's an interesting puzzle. This is called "Rudenko's Disk" (Brainwright) — finding information or solves for it online isn't all that challenging, which would largely ruin the fun here, so ...
7
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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 ...
7
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2answers
871 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 ...
7
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4answers
677 views

Tricky Tricky!-Can you find the secret?

Here's a selfmate problem that just might be baffle you! Thus, I name it "Tricky Tricky!" It's White to move and selfmate themselves in 8 moves. Can you find the secret? As always, no computers ...
7
votes
3answers
217 views

Multiplicative alphametic: This is too hard

Every letter and every question mark stands for a digit in base-10 representation Different letters stand for different digits Question marks are placeholders and stand for arbitrary digits (that ...
7
votes
4answers
184 views

Fill in the boxes to get the right equation v2

My take on a recent puzzle. Place numbers into boxes to create a correct equation, using each number at least once: $$\Box-\Box+\Box\times\Box=\Box\:/\:\Box$$ This time the four decimal numbers are ...
7
votes
2answers
743 views

Password Cracking

You are trying to crack someone's password. You don't have any password cracking software, nor do you have time to get any. From sources unknown, you know that: A. The password is alphanumeric (...
7
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2answers
251 views

Listen to my Story…Let us find the Unique Invisible Pan Digital Pair

I was an avid reader of Popular Science magazine. In the last page or so, they usually had visual clues without words to make useful stuff. I always wanted to create a mathematical puzzle like that ...
7
votes
1answer
393 views

It is as easy as A B C, Figure out U V C from the given relationship

Given $ U, V, C $ are three distinct digits, figure them out from the following relation: $$ \overline{CCC} = \overline{UVUVUV} \div \left ( \overline{UV} \times \overline{UV} \right) $$
7
votes
2answers
487 views

Escape the cube 2 (Theseus and Minotaur variant)

Hello, here is a puzzle I created. I plan to post a few more in the near future. If you like it, google Cubiscape for more. Goal: You are the blue ball and have to get to the green square without ...
7
votes
2answers
336 views

How many dates are ambiguous across the Atlantic?

The Day/Month/Year date system commonly used in Britain (and much of Europe?) and the Month/Day/Year system commonly used in the US can lead to confusion when, for example, we write 9/3/2018 for the ...
7
votes
2answers
320 views

Arrange numbers to 3x3 square with concentric (Addition and Difference)

2 Similar questions: I. Difference Arrange numbers 1 to 8 to replace the letters so: A = abs (B – D) C = abs (B – E) F = abs (D – G) H = abs (E – G) To eliminate duplicates by rotation and ...
7
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2answers
458 views

The Chessboard Exhibition

Why not, another entry in Fortnightly Topic Challenge #41: Short and Sweet I just bought the newest, coolest chessboard! I think I'm going to share it to my five chess pieces at the National ...
7
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1answer
970 views

Aiming for the 24

6 1 3 4 = ?? Using four basic math signs (+, -, *, /) and brackets, for instance: 6 * (1 + 3) - 4 = 20 6 * 1 * 3 + 4 = 22 6 + 13 + 4 = 23 (6 + 1)* 3 + 4 = 25 61 - 34 = 27 Try ...
7
votes
2answers
653 views

A very evil cipher

A very evil tyrant locks you in a very evil cellar in a very evil castle. Every day he brings you a bit of soup and a bit of bread with a message he says, "It's the code but you have to decipher it ...
7
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1answer
337 views

1 crossword and 2 connected alphametic (more clues)

Rules : Solve the Crossword. The words can be written backward (example zebra -> arbez) After finishing the crossword, solve the alphametics. The crossword is only uses 10 letters. Each letter ...
7
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2answers
315 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 ...
7
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2answers
333 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.
7
votes
1answer
151 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 ...
7
votes
2answers
267 views

A Criminal Conspiracy (Who Is Guilty #4)

[Appeal: I'm trying to figure out a fun puzzle formula. There are many out there ("Who owns the fish", sudoku, etc). I'm interested in feedback on whether this works or is interesting for people. ...
7
votes
1answer
383 views

Arrange numbers to the triangles, so the sums are equal to S

Rules: Arrange numbers from 1 to 11, and each number can appear max twice. The numbers are arranged, so that any 3 numbers which forming an up-triangle sum to the desired number (S). A equal sign ...
7
votes
1answer
710 views

A Game with Strings and Coins

Alice and Bob play a game using the following arrangement of coins, which are joined by strings and hanging from the ceiling: $\qquad\qquad\qquad\qquad\quad$ The two alternate turns, with Alice ...
7
votes
2answers
186 views

Puzzling Knight has a Message for all- Especially Newcomers

Of all the more than a Trillion messages he can deliver, he has especially selected this message for all. Follow his(normal chess moves for the Knight) path to get the message. His journey starts ...
7
votes
1answer
2k views

Find the missing numbers in the magic square

The following is a magic square: each row, column and diagonal add to 34, all of the numbers 1 to 16 appear exactly once. Find the missing numbers.
7
votes
1answer
314 views

Escape the cube puzzle

Hello, here is a puzzle I created. I plan to post a few more in the near future. If you like it, google Cubiscape for more. Goal: You are the blue ball and have to get to the green square without ...
7
votes
1answer
222 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 ...
7
votes
1answer
546 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 ...
7
votes
2answers
274 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! ...
7
votes
1answer
192 views

Stars of the Celestial Bagua

Check this out: Okay, it might be more impressive if I show you what is moving along the arrows: At every vertex in a long word. Flowing in to every vertex are two short words ("inputs"). ...
7
votes
1answer
181 views

Unsolving a Rubik's Cube

A few days ago I picked up a solved Rubik's Cube that I had abandoned due to forgetting how to solve it, and started turning the faces to make nice patterns. A few minutes later, I'd made one - each ...
7
votes
1answer
212 views

Excited Raichu vs the Dream (Chess Puzzle)

(Source: An actual tournament game I played all the way back in 2016) I had the weirdest dream last night… It started out normal enough, which for me, is basically nothing… but then I woke up, ...
7
votes
1answer
203 views

Subtraction square dance alphametic

Every letter stands for a digit in base-10 representation, different letters stand for different digits, and leading digits are always non-zero. ...
7
votes
2answers
466 views

Pensive Nonogram - Two-Colour Puzzle

Fourth two-colour puzzle in the 32nd issue of Mega Pixel Puzzles by Puzzler.. I’ve made some progress, but I am stuck. Can you help me find my next move in it? (The puzzle is below)
6
votes
4answers
3k views

Are perfect cubes possible?

Based on this. Can you find 4 distinct integers a, b, c, and d such that a+b, b+c, c+d, a+b+c, b+c+d and a+b+c+d are all perfect cubes? If not, prove it.
6
votes
8answers
1k views

A word exercise : Same consonants and five vowels [duplicate]

Can you think of 5 different 5-letter words which use the same 4 consonants and each word includes one separate vowel? You must use all 5 vowels. In all 5 words, the 4 consonants and one vowel must ...

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