Questions tagged [no-computers]

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

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
votes
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
votes
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
votes
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
227 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
321 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
165 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
188 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
113 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
votes
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
377 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
120 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
199 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
173 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
599 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
7k 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
162 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
5k 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
651 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
288 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
425 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
710 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
159 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
388 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
791 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
199 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
404 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 --------------...
8
votes
5answers
697 views

The distance between David and Eric

Alice and Bob are looking at each other, both turn $10$ degrees and now they both can directly see Claire. If they continue turning in their same directions before, Alice will directly able to see ...
11
votes
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 ...
4
votes
7answers
321 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
votes
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 ...
4
votes
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 ...
15
votes
2answers
1k 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
votes
1answer
537 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
votes
1answer
339 views

Which letter completes this puzzle?

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

Can this be undone to make a knotless loop?

Can this be undone to make a knotless loop?
1
vote
2answers
427 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 ...
1
vote
2answers
663 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 ...
9
votes
2answers
6k views

Crack the 5 digits code

I created this "crack the code" puzzle. I hope the members here like it.
30
votes
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,...
2
votes
1answer
625 views

Move 2 or 3 spaces in this 5 by 5 grid

You have a 5 by 5 Board as shown. You start from the S (Center) position. You can: 1 Move TWO or THREE spaces only 2 You can move Vertically or Horizontally or Diagonally but only in a straight ...
4
votes
1answer
562 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&...
10
votes
1answer
650 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
votes
3answers
366 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
votes
1answer
966 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 ...