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

7
votes
3answers
540 views

No spanish required

Each letter represents a digit, so what is Mucho and Poco (although who's to say?) ...
9
votes
4answers
2k views

A poorly-designed chess problem

Entry into Fortnightly Topic Challenge #40 Out of character comment: For effect, don't open up the next spoiler until you've finished the statement before. If answering, please explain each remark. ...
2
votes
1answer
89 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, ...
4
votes
1answer
153 views

The Wheel of Judas

I was studying up on some pretty archaic methods for testing intelligence and I came across one called The Wheel of Judas. It is said that if you were able to fully solve the wheel that you were a ...
3
votes
1answer
128 views

Facing four mate threats

Just a regular chess puzzle. White to move and win.
1
vote
0answers
125 views

An Antichess Puzzle

There's a fairly popular alternate version of chess called Antichess, or Losing Chess, or about seventeen other names. In this variation, the pieces move as usual, but the rules are slightly altered. ...
17
votes
6answers
3k views

Nobody likes this compound word

This compound word, that no-one likes, is made up of 3 consecutive words. Also made up of 2 consecutive words. Also the prefix and suffix are identical words Uses only 3 consonants. ...
12
votes
2answers
320 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 ...
2
votes
1answer
120 views

Row of alternating coin

I stumbled upon a mathematical puzzle that goes like this: You have 2n coins that alternate between head and tail. For example, if n=3, then it looks like H T H T H T, where H = head and T = tail. To ...
2
votes
1answer
116 views

Some Really Confusing Math

I was talking to a co-worker this morning and he stated that he was able to make both of these statements true using only $1, 3, 5,$ or $ 7$. He then proceeded to tell me: $1 = 5$ $2 = 4 + 7$ $3 = 1$ ...
5
votes
2answers
1k views

Did Grandpa count correctly? Another Grandpa Mystery

Grandpa just returned from a long trip. He started telling me about his adventure in a wild place. " I saw animals", he said. "Three different kind" "Just for fun I counted their limbs" "...
3
votes
2answers
136 views

$109088$ as sum of $3$ palindromes

One can write the number $109088$ as the sum of two palindromic numbers as follows: $$109088 = 99199 + 9889$$ Note that the numbers on the right are both palindromes (read the same left to right as ...
4
votes
0answers
123 views

A small team doing their job

Find the unique solution to $$ 5\,ninja + retook + quarter + turn = \_\,\_\,\_\,\_ + \_\,\_\,\_\,\_\,\_\,\_\,\_\,\_\,\_\,\_ $$ where each unknown is a different _ _ _&#...
6
votes
3answers
364 views

Calculator Bomb

So, I need your help. I got home after a long day and found a calculator roughly taped to my door. However, there was something much more disturbing attached to that calculator. It was some kind of ...
7
votes
4answers
159 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 ...
1
vote
2answers
95 views

A Fairly Simple Equation #2

I got a lot of positive feedback on my last puzzle, A Fairly Simple Equation (even though it was apparently a lot easier than I thought it would be!) So, I've got another similar puzzle. General ...
3
votes
3answers
139 views

A Simple Math Puzzle

So my last math puzzle was too easy apparently, and this one might be too. Either way, the rules are the same. No rotation. No duplication. No combination. No rounding. No computers. Good luck to ...
6
votes
3answers
522 views

My First Math Riddle

Okay, so I write a lot of Riley and story riddles; however, I've noticed that I like the mathematical riddles too! I decided to write one, and I hope you all enjoy it. A few rules: No rotation. No ...
10
votes
7answers
735 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
9
votes
1answer
113 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, ...
3
votes
1answer
155 views

Does he like them or not? Another Grandpa Mystery

Now I know very well the weird likes and dislikes of Grandpa. Yesterday he tells me: "Son I like Queen but not the Queen I liked the King but not the King I like Monarch but not ...
19
votes
3answers
2k views

Which two houses didn't get any mail that week?

Postman delivers the mail in the small village. This village has exactly ten houses, numbered from 1 to 10. In a certain week, he did not deliver any mail at two houses in the village but at ...
0
votes
1answer
85 views

Jabberwocky Question

What's a good word to describe 'Jabberwocky,' by Lewis Carroll? As a reminder, here's the first stanza: 'Twass brillig, and the sluithy toves Did gyrre and gimble in the wabe; All mimsy werre ...
1
vote
0answers
103 views

center of the noise [closed]

In the center of the noise, the accused tries to hide. But the demons are already around, they take control.”? SOURCE
7
votes
1answer
956 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 ...
8
votes
3answers
341 views

How can 15 become 3?

This is not a mathematical puzzle. How can 14 become 7? 10 becomes 1, but can also become 2. 13 becomes 8, and 8 becomes 10. 6 stays as 6 under this thinking. Hint 1: Since answer was found, OP ...
6
votes
8answers
988 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 ...
1
vote
2answers
116 views

I like to stuff things in my gut

What am I? I like to embrace pretty much everything in life, And I am obsessed with a popular essential oil. I chew on gum pretty much all day, And don’t drink a lot of water. I ...
4
votes
1answer
151 views

A special square

Is there a four-digit square number which has at least one digit in common with every other four-digit square?
2
votes
2answers
155 views

Tiling rectangles with a Heptomino plus 2x2 square

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 ...
18
votes
4answers
1k views

A mazegic square

So you like mathematical diversions? Here's something new for you then ...
1
vote
2answers
113 views

Tiling rectangles with Heptomino plus rectangle #7

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 ...
11
votes
2answers
468 views

Ziggy - Make a square from 8 polyomino pieces

A few years ago I created a small packing puzzle that I'd like to share here today. The puzzle is based on the fact that $1+2+3+4+5+6+7+8 = 6^2$. It consists of 8 zig-zag polyomino pieces, ranging in ...
10
votes
1answer
356 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
506 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
129 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
83 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
358 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 ...
15
votes
1answer
506 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 ...
33
votes
1answer
1k 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
257 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
242 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
370 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
157 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
437 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
votes
5answers
996 views

Color Logic problem 3

Find the rule specified in the image below. Make sure the rule fully satisfies. Part two and one
11
votes
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 ...
16
votes
2answers
672 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
628 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
641 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 ...