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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14
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1answer
295 views

E's-y T's: Word square fill in

This is a follow-up to E's-y Word-Square Fill-in, but you don't need to know anything about that puzzle to solve this one. For each word square below, the Es and Ts have been filled in for you. ...
14
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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 ...
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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’&...
14
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1answer
394 views

The road to El Dorado reconstructed from fragmented accounts

You are seeking the route to the lost city of El Dorado. You have assembled several historical accounts from explorers who claim to have reached it. Unfortunately, the accounts are incomplete, ...
14
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1answer
880 views

4x4 Sliding Puzzle with a twist

For this puzzle, you're given a three piece set as depicted below: A blue indicator peg A square 4 x 4 tile frame filled with 16 tiles A max.8 tile holder / dispenser Your task is to un-scramble ...
14
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1answer
325 views

A small team doing their job

Find the unique solution to $$ 5\,ninja + retook + quarter + turn = \_\,\_\,\_\,\_ + \_\,\_\,\_\,\_\,\_\,\_\,\_\,\_\,\_\,\_ $$ where each unknown is a different _ _ _&#...
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5answers
4k views

How often does a digital watch show a palindrome?

A palindrome is a word, phrase, number, or other sequence of characters which reads the same backward or forward, such as madam or kayak. We have a digital watch showing the time HH:MM:SS as shown in ...
13
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4answers
2k views

77-digit number divisible by 7 with seven 7s

The smallest number divisible by 7 with seven 7s is trivially 7777777. Then, what is the greatest 77-digit number divisible by 7 which contains seven 7s?
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3answers
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Want to go from MANILA to UGANDA

How do you get from the word MANILA to UGANDA in the shortest time? You can change up to 3 letters at a time to form a new 6 letter word which MUST be either a country name or a capital of a country. ...
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3answers
768 views

Pythagorean triplets wheat field

A rectangular field has width $a$ and length $a+1$. We cut it into 3 triangles that all have integer side lengths. If all triangles have a different area, then what’s the minimum value of $a$? Please ...
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2answers
745 views

Digit sums of successive integers

For a natural number $x$ both, the digit sum of $x$ and the digit sum of $x+1$ are multiples of $7$. What is the smallest possible $x$?
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3answers
865 views

And now you see it II (the B side)

It amuses me that the word CANOES has been there in VOLCANOES all along. And URCHIN is barely hiding in the word LURCHING. And ASPIRIN is right there in ASPIRING. SISTER is in RESISTER. AKIN is in ...
13
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1answer
911 views

Dear Fellow PSE Users,

This puzzle is dedicated to all of you! Instructions There are 8 anagram questions below. In each question, you can rearrange the letters to find an answer, which is 2 English words that describe a ...
13
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1answer
411 views

Infinite Sequence based on Simple Rule

Using one simple rule, an Infinite Sequence has been developed. First 30 terms are given. Can you continue the sequence for at least next Ten Terms? Series continues from top left to bottom right. $...
13
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2answers
862 views

Delete a digit then sum

Take a number $(x)$, then create the complete list of the numbers formed by deleting single digits from its base ten representation $(d_1,d_2,...,d_n)$. If the sum of those new numbers equals $x$ we ...
13
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2answers
787 views

Hit the Bulls Eye with T in the Center

There are 3 Rings with “T” in the center. In each ring, letters are distinctly different - 16 in the outer, 8 in the middle, 4 in the inner rings. Hit the Bulls Eye by making sixteen different four ...
13
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1answer
429 views

Candy Button Paper

An entry in Fortnightly Topic Challenge #35: Restricted Title 1. Title based on this xkcd. Your biggest dream has come true: you have an infinite supply of your favorite five-flavor candy button ...
13
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1answer
518 views

The tip of a colorful triangle

Original source: Problem 1 of British Informatics Olympiad 2017, Round 1 You're given a bunch of red (R), green (G), and blue (B) balls. I arrange some balls on a line. Then I ask you to complete the ...
13
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2answers
596 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? ...
13
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3answers
833 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, ...
13
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1answer
216 views

No Halves Hath the Heptagram

Here is the heptagram: Rules are the same as for the octagram. However, the heptagram has the very nice property that all words are unique. I.e., as you go around, you will not encounter any ...
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3answers
415 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 --------------...
13
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1answer
268 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 ...
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5answers
2k views

Maximise your gold!

You met a genie. He gets $150$ magic lamps out, which are numbered from $1$ to $150$. You have to colour each lamp red or blue. After colouring, the genie will count the number of triples $T$ of magic ...
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4answers
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The Special Numbers

Let's try to find out the numbers satisfying the cryptarithms below; $ab=(a+b)^2$ $abc=(a+b+c)^3$ $abcd=(a+b+c+d)^4$ There are only 3 unique answers! Note: $a$,$b$,$c$,$d$ are all ...
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4answers
875 views

Find the three digit Prime number P from the given unusual relationships

$Given:$ P is a 3 digit prime number Q,R,S,T are distinct digits( 0 to 9 ) QRS is a concatenated number $Relationships:$ $P$ = $QRS + T$ = Reverse of $( QRS * T)$ Find P using just ...
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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? ...
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2answers
371 views

Cannibalistic Words

Drawing from the word pool below, find the twelve Cannibalistic Words. (Note the no-computers and logical-deduction tags.) WILD _ _ ☐ _ _ _ _ ☐ PENS ☐ _ _ _ _ ☐ _ _ DEED _ _ _ ☐ ☐ _ _ _ BLED _ _ ☐ _ ...
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3answers
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One year celebration

I've got notified a few days ago from PSE that my account on this website is 1 year old. So I thought about celebrating it (or commemorating it, because you all made me addicted to this) with a puzzle ...
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2answers
2k views

My Graph Theory Students

I have 18 students in my graph theory course this semester: Anne, Bernard, Clare, David,..., and Rachel. At the start of the course I asked them to draw the graph below, in which each of them is ...
12
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1answer
3k views

Two dead beans on a stone

Samuel Bean, a Canadian doctor, had a tombstone erected in Rushes Cemetery near Crosshill, Wellesley Township, Ontario, for his first two wives, Henrietta and Susanna. The original stone was carved in ...
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2answers
797 views

Hearts and Spades in a Row

From a deck of playing cards remove hearts ace to seven, and spades ace to seven. Now place them on a table in a row so that the number of cards between the two aces is 1, the number of cards ...
12
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1answer
478 views

An odd looking Sudoku

Somewhat in the spirit of Stiv's This new puzzle type needs a name, can you solve this odd looking Sudoku and give it a name?
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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 ...
12
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1answer
479 views

Resolve this Fibonacci Relationship

$Given$: $A$, $B$, $C$, $E$, $F$ are distinct digits varying from $1$ to $9$. $A$ is a Fibonacci number. $BB$, $BC$, $EF$ are concatenated Numbers. $Relationship$: $(A*BB)*(BC)^2$ = $(EF)^2- B$ ...
12
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2answers
452 views

Comparatortionist: The $M_Q$ Functor

The Problem At the intersection of mathematics, computer science, and insanity, we find the $M_Q$ functor${}^1$. $${M_Q} = {\Phi _{{s_1},{s_2}}}\left\{ {\begin{array}{*{20}{l}} {E \leftarrow {\Phi ...
12
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1answer
314 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. ...
12
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1answer
537 views

A broken mosaic of words

In this puzzle, you'll have to rebuild words using the "pieces" listed at the bottom and place them in the grid provided below. Some notes about this puzzle: The gray cells with the dotted border are ...
12
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1answer
517 views

A Puzzling Cryptex

I was hanging out in the Puzzing.SE lounge (the beanbag chairs are heaven) when some random person walked up. They said, "I love this place! Would you try my puzzle?" Their puzzle was a cryptex (...
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4answers
385 views

This word is a name. Also a Surname

Starts with a place, ends with a place Starts with a number, ends with a number Starts with a surname, ends with a surname A word to the wise. Only one vowel- used twice. Can you guess,...
12
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2answers
309 views

A fraction puzzle

This is a puzzle with both the computer-puzzle tag and the no-computers tag. We have the following list of five fractions: $$11/5, 30/77, 1/11, 21/2, 5/7.$$ Starting with an integer x, we perform the ...
12
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2answers
417 views

The art of computer programming

EDIT: I know we are not supposed to edit in new requirements after first posting but as far as I understand it this requirement is implicit in all questions here: Explain your answer! At least a ...
12
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1answer
190 views

This compound word is a fun thing

Here is an interesting compound word It has all the 5 vowels but used only once (no repeat of the same vowel) It has 4 consecutive words that include 2 names. It starts with a name and ...
12
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1answer
424 views

Humans, vampires and mirrors

Here is a room composed of $10 \times 10$ squared cells. Some cells contain a double-faced mirror ( / or \ ) that reflects the light with an angle of $90°$ on both sides. The other cells can be empty (...
12
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1answer
237 views

An alphametic for René Descartes

The best known philosophical statement by René Descartes is "Cogito ergo sum" (French: Je pense, donc je suis; English: I think, therefore I am). ...
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2answers
546 views

KenKen Zen: A journey begins

Let us shy away from the materialistic opulence of 361- cell KenKen layouts (−9 to +9, squared).  Let us contemplate a modest KenKen journey, unburdened by gratuitously ...
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4answers
4k views

Use 1 9 6 2 in this order to make 75

I'm looking for a solution to make number $75$ with numbers $1$ $9$ $6$ $2$ in that order and the same rules as in Use 2 0 1 and 8 to make 67. Here a copy of those rules: You must use all 4 digits. ...
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5answers
2k views

Nice no-computers way to find limerick primes?

A limerick number is a 5-digit number whose digits are in the form of a limerick rhyme scheme: $aabba$. How many limerick primes (limerick numbers which are also prime) are there? The answer is ...
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7answers
2k views

Fill in the boxes to get the right equation

Here is a math puzzle I had a little bit of hard time with No computers please There is a solution without inverting 6 to 9
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6answers
2k views

Coke alphametic

The only thing I love more than Coke is numbers divisible by 73. I claim I have found a unique assignment of distinct digits $0,1,...,9$ to the symbols $ C, O, L,$ and $A$ such that $73$ divides the ...

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