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.

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4
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1answer
170 views

Slightly bigger 1:2 hand tiling, getting a little harder

Pretty sure an expert hand tiler would be able to find this. Please post a spoiler only if you hand tile it... Tile a $60\times60$ square with $1:2$ rectangles of sizes ...
4
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1answer
204 views

Two similar hand tiling puzzles

Make a square from each of these lists of aspect ratio $1:2$ rectangles 1, 4, 5, 6, 7, 9, 11, 12, 13, 14, 15, 17 ...
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2answers
274 views

Trickier hand tiling

This should be a little trickier. Using $20$ rectangles of aspect ratio $1:2$, make two squares. Use sizes 2,3,7,12,16 in both squares. And split this list among ...
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3answers
2k views

A magical operation

A magical operation on a particular number (not ending by 0) is the addition of this number with his symetrical number. For example the magical operation for 2018 would be 2018 + 8102 = 10120. Let ...
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1answer
2k views

Make numbers 0 - 11 using the digits 2, 0, 1, 8; BUT

... seriously, this is definitely NOT that "kind of puzzle"! ;) So let me create this puzzle to freshen you up! It is inspired by a meta question: Yet another 2018 puzzle. Put the digits 2, 0, 1, ...
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3answers
500 views

How many 5+ letter words can you find?

NYT does a word hive in every Sunday edition, and I quite enjoy it, so I decided to make my own, using the same rules. Check it out: If you're unfamiliar, here are the rules. You may only use the ...
3
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1answer
121 views

Dissect a square into 1:2 non-congruent integer-sided rectangles

(Similar to the recent 3:1 and my 3:2 rectangle question) Tile a square completely with rectangles which have aspect ratio 1:2, integral side lengths and all different sizes. In other words selected ...
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2answers
3k views

The Ultimate Typo

Here are four sentences that I made up. But I accidentally shuffled the characters in every column! Can you figure out what the original sentences were? ...
10
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1answer
406 views

So many names in this place

The spelled name of this one word place is kind of interesting It has within its name: Three first names One last name One name of a country One name of a Province/State/Territory One ...
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5answers
2k views

Optimal Money-Saving on the NYC Metro

You are on vacation in New York City. You didn't bring your car, and it's currently around $-50^\circ C$, so it's probably a good idea to take the NYC metro subway to move around. You need a metro ...
3
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1answer
127 views

Hand tiling puzzle 2

Here's another set of polyominoes (sizes 4,5,6,7,8,9,10) that you can print and cut out. As before, the two smallest (same pieces as previous version) make a 3x3. The rest of the pieces are different. ...
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3answers
220 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 ...
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2answers
686 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 ...
6
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1answer
235 views

How many dimensions?

You have $n+1$ points in $n$-dimensional Euclidean space, such that the mutual distance between each pair of points is the same. Now imagine an $n$-dimensional generalization of a sphere, such that ...
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10answers
11k views

A word pronounced like letters

Can you give me a word that when pronounced, sounds exactly like pronouncing some of the letters of the alphabet. For example The word TEEPEE sounds exactly like the letters T and P so TP, just as ...
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3answers
416 views

Gone ortho-flogging

 Well played, Scratchy, you just took 8 shots on Hole 9 of Puzzlington Municipal Ortho-flog Course! As presented As flogged (solved) by you --------------...
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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 ...
28
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8answers
6k views

Another Easy Mate in 1

Standard chess rules apply, the board is not rotated (i.e. white pawns move upwards), no lateral thinking is needed. Simply find the one move for white which mates the black king. This puzzle was ...
5
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4answers
880 views

Word list: 2 consonants 2 vowels

Original 4 letter word Two consonants Two Vowels All next words use the exact same 2 consonants and exact same 2 vowels. Order not important Next word 5 letters Same 2 consonants same 2 vowels ...
12
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1answer
319 views

Multibranched tree

The Furca Fractalis tree grows in a very special way. Starting with the trunk there are three possibilities to continue growing: It can split in two branches. It can grow one branch and one leaf. ...
10
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1answer
553 views

An incomplete set of numbers

Here's a fun math thing: Imagine building a set of non-negative integers, starting with zero. As you check increasing numbers, you add it to the set if doing so does NOT create a subset of three ...
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1answer
1k views

Fill in the 3 letter blanks

Please fill in the 3 letter blanks in the following numbered list 1 --- 2 CAD 3 --- 4 CNY 5 --- 6 AUD 7 --- 8 ARS 9 --- 10 --- Please no computers/internet. A complete list would ...
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8answers
2k views

How many coins did Mrs. Jones have?

Mrs. Jones is celebrating her 43rd (Prime number) birthday. Over the years she has collected gold coins. The number of coins is a Prime number less than 100. She decides to give all the coins to her ...
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2answers
294 views

Find a Strobogrammatic number, so if we square it, the result is a pandigit number

Find a Strobogrammatic number, so if we square it, the result is a pandigit number. Note : A Strobogrammatic number is a number when typed on a calculator, and the calculator is spun 180 degrees, ...
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2answers
165 views

Polygon neighbors

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 ...
72
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2answers
6k views

Oh dang, I have to change my whole answer!

One day, you enter your math classroom. On the board, there are the words POP QUIZ. Dang it! Was it about fractions? you knew you were bad with fractions. You look down. $\begin{array}{|cc|} \...
6
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3answers
471 views

Lucky Lottery Tickets

Six-digit lottery ticket numbers are considered lucky if the sum of the first three numbers is equal to the last three. Eg. 123204, 871529... Prove that all possible lucky numbers added together is ...
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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 ...
30
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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,...
10
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1answer
235 views

Irrationality in the balance

Sensibilly -T ™ scales were out of stock, so Gramazon filled the order with a lousy Lopside® from Irreturnable Irrationals International, Inc.73205080...  How ...
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7answers
4k views

Find the longest string of words such that the (4 letter) end of one word is the start of the next

Here is an open-ended challenge. Find the longest series of English words such that the final four letters of word $n$ are the same as the first four letters of word $n+1$. Example (3 words) ...
11
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1answer
1k views

What are these numbers?

A simple (I think) alphametic puzzle $\small{MADMEN = (M+A+D+M+E+N)^{((M+E+N) - (M+A+D))}}$ M,A,D,E,N are different (no repeats) positive integers between 0 and 9 and of course the 2 Ms are the ...
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3answers
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’&...
4
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7answers
370 views

Sum of three six digit numbers

This puzzle is a variation of a 3 digit addition puzzle I saw recently. A , B , and C are positive integers between 0 and 9. A,B and C are different integers Six digit numbers formed using A,B and ...
4
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4answers
2k views

Three words with three animals

Can you give me at least 3 ( I found 4 so far) Five Letter words with at least 3 animal names spelled in them? No anagrams (rearranging letters). The 3 animal names must be in ONE WORD. Find 3 ...
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6answers
1k views

Tom's mysterious alphanumeric character

Tom: I drew a mysterious alphanumeric character and showed it to Harry. Dick: Harry, was it a letter or a number? Harry: I'm not sure! Dick: Assuming it was a letter, was it uppercase or ...
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2answers
2k views

What's the missing pattern? 3x3 grid, dot pattern

What is the missing piece to this pattern? Got it as a quiz at work - no one here knows what it is!
3
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1answer
615 views

The SUM 50 Game

Attached Grid (Total 5 x 5) has a black box grid (3 x 3) inside it. The Black box grid needs to be filled out with numbers 1 thru 9 using all numbers once. The Outer Red box squares (Total 16 ) need ...
0
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1answer
360 views

Which letter completes this puzzle?

As shown in picture below, which letter completes the puzzle ? It bogging me for few days already ...
5
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2answers
250 views

Can this be undone to make a knotless loop?

Can this be undone to make a knotless loop?
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2answers
490 views

My Friend, 4 kids and gold and silver coins

The other day I met an old college friend in a coffee shop. We both were students in the Math department of that college. Here was our conversation (after the small talk) We are meeting first time ...
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2answers
916 views

solve this 8-puzzle

This quiz is about the 8-puzzle. It is a board with 9 fields. There are 8 tiles with numbers from one to eight. One field is empty. You can slide numbers around the board: But only numbers next to the ...
15
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2answers
1k views

Find out the rule, then solve it

First, Find out the rule from the example, Then solve the puzzle without computer. The answer must be unique (just 1 valid answer). Example Solve This
4
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1answer
690 views

Beating at Eating, a logic-grid puzzle for literal logicians

$\begin{array}{r|lll} &\text{Name}&\text{Surname}&\text{Dessert}\\ 1&\text{Agatha}&\text{Greed}&\text{cream puffs}\\ 2&\text{Bugsy}&\text{Forager}&\text{trifle}\\ 3&...
13
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2answers
613 views

A mo-Roman sampler

    Pluck some relatively easy mo-Roman mini-puzzles while there’s relatively easy pickin’s. What two English words, taken as mo-Roman numerals, form the same number? ...
10
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1answer
1k views

How to play Japanese mahjong part 1: Forming hands

Have you ever wanted to learn mahjong but thought the game was too complex to get started? Well this puzzle will help you learn the basics of forming hands! So come on, what are you waiting for? ...
7
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3answers
457 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 ...
5
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1answer
1k views

Difference square logic (5x5)

Rules : Arrange numbers 1 to 25 to the squares, and each number only occurs once. Green squares are the difference from its left square and its right square. Green squares are also the difference ...
2
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1answer
468 views

Chess : flawless victory

-warning : true story alert- In my high school years, I used to be in the chess club. One day, my friend taught me the famous 4 move win and told me how it was "the best, the fastest, most awesome ...
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2answers
142 views

How many answers are there to this alphametic?

If you take a problem of the form: abc +def ---- ghij where each letter must be replaced by a different digit (that is, all digits, 0-9 must be used once), how ...

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