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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18
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1answer
413 views

2 Knights tied together in a dangerous maze

2 knight pieces of the game chess were trying to find their way to freedom, while being tied together with a small rope. It was so small that it forced them to be placed in adjacent squares at all ...
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2answers
2k views

We are two immediate neighbors who forged our own powers to form concatenated relationship. Who are we?

Our concatenated number is $ \overline{ABAC}, $ where $ A, B, C $ are all positive digits (1 - 9). Our relationship is $$ \overline{ABAC} = A^A + B^B + A^A + C^C $$ Who are we?
17
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5answers
2k views

Second-rate spelling

Find the longest word which can be spelled with the second letters of a group words in alphabetical order. An example with incomprehensible (16 letters): a...
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4answers
2k views

Paint 21 Squares of a 7×7 Board Without Forming a Rectangle

Got a nice puzzle from my friend, when he was competing in IWYMIC/IMC 2011. Paint $21$ of the $49$ squares of a $7 \times 7$ board so that no four painted squares form the four corners of a rectangle....
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2answers
719 views

The Amazing Sliding Crossword

Solve the crossword then slide the blocks to create another configuration with eight new words. Across 1. Lure 5. Before long 6. Frosted 7. Permit Down 1. Scold 2. Formerly 3. Frost, for ...
17
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1answer
964 views

Son of the Revenge of the Riley Riddles in Reverse Strikes Again

Because why not, here's yet another bunch of these inverted riddles, where the solutions are what you'd usually use as the wordplay clues in a Riley Riddle. Here's how it goes: You get three words. ...
17
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2answers
1k views

Oh, woe is me, the creature's back

Oh, woe is me, the creature's back to give me certain heart attack! He's plucking words and shifting glyphs. What sort of devilry is this? I love the gates of hell; I’m kind of a rod (6) The apple ...
17
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3answers
316 views

Pairs of Pairs of Pentominoes

Split the 12 pentominoes into three sets of four. Can you pair up pentominoes so that each set makes two of the same shape? For instance, one of your three sets could look like this: That uses the L,...
17
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1answer
1k views

The Lord of the Puzzles

In 1904 (at the age of 12) J.R.R. Tolkien sent a "puzzle letter" (pictured below) to a family friend; Father Francis Morgan. What does it say? Obviously it would be trivially simple to google the ...
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9answers
4k views

Solitaire Chess

A friend of mine got me Solitaire Chess for Christmas years ago. I set up the board below. Is it possible to solve it? If so, what is the solution? (No programs allowed- Use only your brain.) Rules: ...
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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. ...
16
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5answers
2k views

Divisible by seventeen

Determine the smallest integer $n \geq 0$ for which the decimal digit sum of n is a multiple of 17 the decimal digit sum of $n+1$ is a multiple of 17. No computers! The puzzle has a nice direct ...
16
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3answers
3k views

Prime to Prime: Get all first 25 Prime Numbers using up to 4 Primes

The first 25 Prime Numbers are 2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,89,97 Using up to 4 prime numbers and the following mathematical operations, get all the 25 primes. + ...
16
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1answer
713 views

Complete the world's longest self-documenting sentence

Complete the following by filling in the blanks with written numbers to create the world's longest self-documenting sentence. ...
16
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1answer
578 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 ...
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3answers
2k views

A weird pocket calculator

A weird pocket calculator has a numerical display (for digits 0-9) and only two buttons, inscripted $\boxed{D+}$ and $\boxed{D-}$. The first button doubles the displayed number and then adds 1. The ...
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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!
15
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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 ...
15
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3answers
1k views

For which numbers does the order of reversing their digits and squaring not matter?

This was a question made up by a friend who doesn't have SE. Let the function $r:\mathbb Z^+ \rightarrow \mathbb Z^+$ reverse the digits of a number (in base 10) that it is applied to. In addition, ...
15
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4answers
423 views

E's-y Word-Square Fill-in

Not necessarily easy, but "'E's-y"! For each word square below, the Es have been filled in for you. Your task is to complete the rest of the square using only ...
15
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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. ...
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3answers
898 views

Nested word series [humans only]

[This is just a fun little puzzle for humans. We'll see you next time, computers!] It's interesting to think about words contained in other words. How often do we notice, for example, that ...
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
15
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1answer
905 views

Word in a phone call

This is a 6 letter word 123456 these numbers represent the letters in the word. Here is the short phone conversation betweeen 2 friends -Hello -Hi 346 -Hey 2356, where are you? -123456, Europe! ...
15
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3answers
366 views

Some-what-not-with-standing word connections

What words can fill the boxes?   Each pair of linked words forms an uncapitalized unhyphenated word when joined end-to-start according to their left-to-right or top-to-bottom order in the link. ...
15
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2answers
988 views

The 7-numbers crossword

This crossword doesn't have any regular clues, however, all the words are made with the same 7 letters (each of them got a number). No automatic solvers are allowed. CSV version: ...
15
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1answer
340 views

Newton's cradles

I went to one of those discovery stores and picked up a few Newton's cradles, except these have hanging words instead of hanging spheres. Check it out: This one has a starter pendulum with two ...
15
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1answer
1k views

Sum in A Sudoku

Color Blind version: Here's a sudoku puzzle with a twist! The numbers given in the squares are actually the sum of the numbers in that region. For example: 18= Sum of the numbers in the 4 yellow ...
14
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9answers
4k views

Perfect Squares!

A question was asked in a mental ability test yesterday. Write four distinct numbers with these properties: 1. Sum of each pair is a perfect square. 2. Sum of all four is also a perfect ...
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8answers
2k views

But it is not an Enclave

What country (sovereign) lies entirely within (inside) another country, But It is not an Enclave? Two possible solutions
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2answers
1k views

Knight Checker Puzzle

Inspired by this question Here's a quick Knight Checker (a chess variant) puzzle. In case you haven't read the rules to it in the above link, I'll repost them here: Each player begins with 1 ...
14
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1answer
596 views

The numbers on blackboard

The numbers $2020,2019,2018,...,1$ are written on the blackboard from left to right. John repeats the following process until there is only one number left: John chooses the first two numbers from ...
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3answers
1k views

From jafe to El-Guest

Largely inspired by From Puzzling to StackExchange by CodeNewbie From jafe to El-Guest jafe > cafe > cate > cete > cet > get > gest > egest > e gest > e guest > el guest Rules: In any move, you ...
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2answers
2k views

And now you see it

It tickles me that the word TUNA is found within FORTUNATE. And there is a COFFIN in SCOFFING. And who put the LAGER in the VILLAGER? The SKIER in RISKIER? The ROMAN in the MICROMANAGER? The ...
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6answers
1k views

A set of lockers

There is a series of 100 lockers in a school. All of them start closed. Students number 1 to 100 flip an even, two sided coin. If the coin lands on heads, they go through each locker corresponding ...
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2answers
1k views

Make a hexiamond star by hand

Using some or all of the hexiamonds (pictured), make a star. You may flip pieces. The usual tiling rules apply, no overlaps, no gaps. Use only one or none of each piece. Answer is unique. Target shape ...
14
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3answers
526 views

Cross, Dot and Scalar Product

This puzzle may seem off topic; though the motivation and background is somewhat mathematically technical, its solution is purely combinatorial (and quite cute). In multivariable calculus, the main ...
14
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2answers
661 views

A Trip to Ripple Islands

All aboard! All aboard! You have won an ALL-EXPENSES PAID TRIP to the magnificent Ripple Islands! Now, the only price of admission is to solve this little puzzle. It is a Ripple Effect puzzle based ...
14
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2answers
393 views

A series of fortunate transpositions

Using only a sequence of transpositions, see if you can take this: to this: while maintaining English words on each of the three horizontals. At each step, you may transpose any two neighboring ...
14
votes
1answer
576 views

A Compound word full of words

This compound word is full of words. You might say it is made up of 2 words and you would be right. But the first of the 2 words is also a compound word! You might say it is made up of 3 ...
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2answers
729 views

The Etiquette Room

This puzzle can be solved as puzzle on its own, but its solution is also part of Deusovi's Community Metapuzzle. You wake up feeling rather dazed. Your head is pounding. Whatever just happened did ...
14
votes
1answer
289 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
329 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
votes
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
827 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
votes
1answer
324 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
3k 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 ...
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3answers
1k views

Crossword gone overboard

This puzzle is part 24 of Gladys' journey across the globe. Each part can be solved independently. Nevertheless, if you are new to the series, feel free to start at the beginning: Introducing Gladys. ...
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2answers
742 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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