Questions tagged [no-computers]

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

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16
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. ...
16
votes
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
votes
1answer
705 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
votes
1answer
556 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 ...
15
votes
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 ...
15
votes
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 ...
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!
15
votes
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
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 ...
15
votes
4answers
400 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
votes
3answers
890 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
votes
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
votes
1answer
901 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
votes
3answers
357 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
votes
1answer
333 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
votes
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
votes
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
14
votes
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 ...
14
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. ...
14
votes
3answers
513 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
votes
2answers
647 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
votes
2answers
969 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: ...
14
votes
1answer
562 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 ...
14
votes
2answers
684 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
272 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
votes
2answers
312 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 ...
14
votes
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
388 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
votes
1answer
714 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 ...
13
votes
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 ...
13
votes
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 ...
13
votes
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. ...
13
votes
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 ...
13
votes
2answers
724 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 $x$?
13
votes
3answers
858 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
votes
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 ...
13
votes
1answer
866 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
votes
2answers
839 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
votes
2answers
776 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
votes
2answers
751 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 ...
13
votes
2answers
1k views

A Halloween Chess Puzzle

Halloween is finally here, so I thought I'd do a theme puzzle! I love chess, and I wanted to do a chess puzzle... so... (It kind of looks like a jack-o-lantern, okay?) Black to move and ...
13
votes
1answer
409 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
votes
2answers
499 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
votes
3answers
804 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
votes
1answer
191 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 ...
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 --------------...
13
votes
1answer
314 views

A small team doing their job

Find the unique solution to $$ 5\,ninja + retook + quarter + turn = \_\,\_\,\_\,\_ + \_\,\_\,\_\,\_\,\_\,\_\,\_\,\_\,\_\,\_ $$ where each unknown is a different _ _ _&#...
12
votes
3answers
2k views

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. ...
12
votes
4answers
1k views

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 ...
12
votes
4answers
863 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 ...