Questions tagged [no-computers]

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

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10
votes
1answer
386 views

Bumblin' Stumblin' Rumblin' Jumblin'!

This is an entry into the Fortnightly Topic Challenge #36 Jumble® was one of my favorite puzzles growing up. They were quick and fun and relatively easy; they took just long enough to keep me ...
4
votes
1answer
541 views

Five different things and five different clues and five different-----

Please finish the title of this puzzle! Five different things, quite common All come in different size, shape and colour Each word has 3 different consonants Five words share and ...
3
votes
2answers
148 views

Tiling rectangles with Hexomino plus rectangle #3

Inspired by Polyomino T hexomino and rectangle packing into rectangle See also series Tiling rectangles with F pentomino plus rectangles and Tiling rectangles with Hexomino plus rectangle #1 ...
2
votes
2answers
93 views

Tiling rectangles with Hexomino plus rectangle #2

Inspired by Polyomino T hexomino and rectangle packing into rectangle See also series Tiling rectangles with F pentomino plus rectangles and Tiling rectangles with Hexomino plus rectangle #1 ...
10
votes
2answers
407 views

Riley Riddles in Reverse, third helping

Once more! For science! Here's yet another batch of "inverted" Riley riddles. The idea is still exactly the same as before: You get three words. You must find one solution word that you can ...
16
votes
1answer
551 views

Riley Riddles in Reverse, batch 2

"post some more sometime :)" -- user @Dragonrage in the comments of Riley Riddles in Reverse Here's another batch of "inverted" Riley riddles. These still work exactly like the ones before: You ...
36
votes
1answer
2k views

Riley Riddles in Reverse

In the all-famous Riley riddles, you have to guess one word from clues about its prefix, infix and suffix. Here, instead, You get three words. You must find one solution word that you can attach.....
14
votes
2answers
310 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 ...
4
votes
1answer
283 views

A challenging Magic Square

Find a 3x3 Magic Square where each row, column and both diagonals result in positive number 9 You are allowed any of the 4 math operations : add, subtract, multiply or divide. NO OTHER OPERATIONS ...
13
votes
1answer
406 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 ...
6
votes
1answer
179 views

Tiling a rectangle with an odd number of Y pentomoes

Follow-on from Tiling a rectangle with just the Y pentomino Two questions: Find the smallest rectangle that can be tiled with an odd number of Y pentominoes, or prove it impossible Find the smallest ...
9
votes
3answers
552 views

Tiling a rectangle with just the Y pentomino

Inspired by this question series, which was inspired by this question. They give rise to beautiful pictures (at least in the eye of the beholder mathematician) and some nice generalizable solutions. ...
5
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5answers
1k views

Color Logic problem 3

Find the rule specified in the image below. Make sure the rule fully satisfies. Part two and one
11
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2answers
2k views

Here's another Color Logic problem

Find the rule specified in the image below. Note that the rule applies to each row independently so every "true" row is "true" by itself If you are confused about these, here's an easy one: Did you ...
17
votes
2answers
732 views

Color Logic - Find the rule

Find the rule specified in the image below. Taken from Caterpillar Logic, now the app is gone.
7
votes
2answers
649 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 ...
3
votes
2answers
3k views

Strategy for 2x3 Sliding Puzzle

Here's an instance of a $2$x$3$ sliding puzzle: The $2$x$3$ sliding puzzle is just a smaller version of the well-known 15 puzzle. Many guides exist on solving the 15 puzzle, and there are strategies ...
7
votes
2answers
333 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 ...
2
votes
1answer
265 views

A magical operation #2

Quick reminder of what is 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 ...
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 ...
10
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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 ...
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.
19
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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, ...
6
votes
2answers
231 views

Challenging 15 rectangle tiling problem

This will test you, a computer will definitely help. Just one set of $1:2$ aspect ratio rectangles this time, but $15$ of them. Short side only is listed. The challenge is to arrange them into a ...
6
votes
3answers
386 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 ...
4
votes
1answer
168 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
votes
2answers
263 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 ...
4
votes
1answer
192 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 ...
3
votes
1answer
116 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 ...
12
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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
votes
1answer
383 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 ...
3
votes
1answer
121 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. ...
8
votes
3answers
203 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 ...
15
votes
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 ...
6
votes
1answer
191 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 ...
9
votes
2answers
633 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 ...
17
votes
10answers
8k 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 ...
3
votes
1answer
164 views

Simple Homeworlds puzzle

On this site, we have numerous chess puzzles. however, we do not seem to have any Homeworlds puzzles, the game of space kings (yes this can be tagged outer space thank you very much.) Hence, here is ...
28
votes
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
votes
4answers
747 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
votes
1answer
293 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
votes
1answer
466 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 ...
11
votes
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 ...
18
votes
2answers
776 views

Anagram fills all the blanks

Continuing with the theme " Same word fills all the blanks" here is a riddle where the anagrams of ONE WORD fill all the blanks. One concession: Apostrophe allowed. NO using Anagram Solver or any ...
3
votes
2answers
160 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 ...
48
votes
2answers
5k views

Six pyramids in a cube

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 ...
6
votes
3answers
395 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 ...
7
votes
2answers
843 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 ...
10
votes
1answer
201 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 ...
13
votes
3answers
406 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 --------------...