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Questions tagged [no-computers]

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

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1
vote
2answers
223 views

modified 3x3 panmagic squares

This is a modified 3x3 panmagic squares. The square is divided into 2 triangles. Numbers 1 to 9 is arranged to upper triangles. Numbers 10 to 18 is arranged to lower triangles. All rows, all columns, ...
30
votes
4answers
2k views

Breaking the record

There is a record whose value is expressed by a natural number. (The value is strictly discrete, not only continuous and then rounded to a natural number.) However, after the record is once ...
8
votes
2answers
443 views

Alphametic as protest #2

Riddles for all. Since my latest alphametic as protest got a good feedback but my riddle as protest did not, I decided to stick to what works and added a new alphametic as a protest for the riddle ...
0
votes
4answers
553 views

Two opposite onramps one city [closed]

Is it possible to have two freeway on-ramps,(one going north and one going south), and have them both go to the same city?
12
votes
2answers
1k views

Alphabetical Sudoku

Who loves fish? Okay that might sound a bit weird but don't worry, I am still sane. Maybe. To answer the question you must complete the Sudoku below. A word will appear in the highlighted box which ...
17
votes
1answer
373 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 ...
8
votes
3answers
541 views

Gambling with the leading digit of $2^n$

Your gambling friend has come to stay with you and offers to play a game with you as many times as you wish: He chooses an integer $x$ between $1$ and $9$ inclusive, and makes a wager of $\$1$ with ...
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, ...
8
votes
5answers
1k views

A few word puzzles 1

Here are some short word puzzles. 1) What's a not uncommon 7 letter word containing all 5 vowels and "s" and one other consonant (not necessarily in order)? 2) What's a common one syllable word, ...
13
votes
3answers
802 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, ...
6
votes
4answers
359 views

How do you transport 42 cars?

You're a soldier in the dictator's army. The dictator is very impressed with your incredible abilities. He asks you this question: There are 42 cars in this parking lot over there. How do you ...
5
votes
2answers
410 views

Ternary FTW! Or not

One day, I wanted to be able to represent all numbers less than 20 without erasers or computers (Don't ask, OK?) I immediately thought of making cards1. For example, in base 10, you need 2 for the ...
6
votes
4answers
3k views

Are perfect cubes possible?

Based on this. Can you find 4 distinct integers a, b, c, and d such that a+b, b+c, c+d, a+b+c, b+c+d and a+b+c+d are all perfect cubes? If not, prove it.
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 ...
7
votes
2answers
735 views

Last contact in custody

You came so close. The job was going so well. You just never expected that the police would have a surveillance cat. That's what you get for trying to steal things in an age where people are ...
11
votes
6answers
2k views

Coke alphametic

The only thing I love more than Coke is numbers divisible by 73. I claim I have found a unique assignment of distinct digits $0,1,...,9$ to the symbols $ C, O, L,$ and $A$ such that $73$ divides the ...
5
votes
2answers
442 views

Numbers = letters 2.0

SIX + SEVEN + SEVEN = TWENTY This is a standard alphametic, no hidden rules. (An alphametic is a puzzle in which every letter corresponds to exactly one number, ...
3
votes
1answer
165 views

An alphametic for Nikolai Gogol

"Diary of a Madman" (Russian: Записки сумасшедшего, Zapiski sumasshedshevo) is a short story by Nikolai Gogol. MAD * MAN = ASYLUM Which digit does each ...
12
votes
1answer
224 views

An alphametic for René Descartes

The best known philosophical statement by René Descartes is "Cogito ergo sum" (French: Je pense, donc je suis; English: I think, therefore I am). ...
1
vote
3answers
320 views

Alice and Bob Alphametic

Let me tell you a story about Alice and Bob. When they are together it's all fun and games, we know that. But what happens when they are not together? I'll tell you. Alice has an odd feeling. It might ...
4
votes
4answers
525 views

Tick-a-tick Tick-tick

Charlie has two clocks that hold reasonably good time. That is, each clock ticks at a constant rate, but its ticks are not necessarily exactly 1 second apart. The period between ticks is constant for ...
8
votes
2answers
384 views

Minimum number of tries to find the balance!

There are 8 distinct weights and a two-pan equal arm balance scale, and you know the weights' weight order: the lightest is numbered as 1 and the heaviest is numbered as 8 and the rest accordingly. ...
6
votes
1answer
247 views

Geographic alphametic riddle with European flags

Every letter stands for a digit in base-10 representation, different letters stand for different digits, and leading digits are always non-zero. $\quad$ PLUS $\quad$ $\quad$ IS EQUAL TO $\quad$ ...
4
votes
2answers
252 views

Alphametic between Kennedy and Nixon

Every letter stands for a digit in base-10 representation, different letters stand for different digits, and leading digits are always non-zero. ...
5
votes
1answer
870 views

Not MONEY but GIFT alphametic

There is a well-known alphametic story where a poor college student sends a telegram with the words "SEND MORE MONEY" to his parents, asking for more money, and asking to fill in each letter with a ...
6
votes
1answer
167 views

Alphametic twins

Every letter (in left and right summation) stands for a digit in base-10 representation, different letters stand for different digits, and leading digits are always non-zero. ...
3
votes
2answers
111 views

A condemning alphametic

Every question mark and every letter stands for a base-10 digit Different letters stand for different digits Question marks are placeholders and stand for arbitrary digits (such digits also may occur ...
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 ...
10
votes
2answers
809 views

An ugly formula [closed]

Our teacher wrote the following ugly algebraic formula on the blackboard $$(n+\sqrt{n^2-1})^{4/3}+(n+\sqrt{n^2-1})^{-4/3}$$ Our teacher told us that for some positive integers $n$ this ugly formula ...
4
votes
1answer
147 views

Bad grammar alphametic

Every question mark and every letter stands for a base-10 digit Different letters stand for different digits Question marks are placeholders and stand for arbitrary digits (such digits also may occur ...
7
votes
1answer
200 views

Subtraction square dance alphametic

Every letter stands for a digit in base-10 representation, different letters stand for different digits, and leading digits are always non-zero. ...
3
votes
3answers
577 views

Ten types of stamps

The country Dalgonia issues stamps of only ten different denominations: $134$, $135$, $136$, $137$, $138$, $139$, $140$, $141$, $142$, and $143$ cents. What is the largest amount of cents which ...
9
votes
1answer
258 views

Not the “SEND MORE MONEY” alphametic

There is a story that a poor college student sent a telegram with the words "SEND MORE MONEY" to his parents, asking for more money, and asking to fill in each letter with a different digit in order ...
4
votes
2answers
179 views

Square dance alphametic

Every letter stands for a digit in base-10 representation, different letters stand for different digits, and leading digits are always non-zero. ...
11
votes
1answer
405 views

Watch the video and figure out who stole the documents?

Ms. Shipra is a renowned scientist in TIFR, Mumbai. She recently discovered a new way of gaining huge energy from the water-current at a much lower cost. Considering its future application, many ...
9
votes
2answers
182 views

An almost Shakespearian alphametic

Every letter stands for a digit in base-9 representation, different letters stand for different digits, and leading digits are always non-zero. ...
11
votes
3answers
680 views

Three positive integers

Find the smallest possible value of $ab+c$, where $a,b,c$ are positive integers with $a+bc=2016$. (No computers! The puzzle has a nice direct solution.)
3
votes
1answer
140 views

Anakin, Obi-Wan and Dooku are a match for Sidious!

Darth Sidious is too powerful. Anakin and Obi-Wan discusses and convinces Count Dooku (Darth Tyrannus) to fight against his own master. It is the only way they can be a true match against the Dark ...
8
votes
1answer
137 views

A very different Alfred E. Neuman alphametic

Yesterday I posed an Alfred E. Neuman alphametic with multiplication, and today I pose an Alfred E. Neuman alphametic with division for the lovers of Mad magazine: Every letter and every question ...
7
votes
3answers
957 views

A bad and boring riddle, and an easy alphametic

First comes the bad and boring riddle (the answer is to be written in all capital letters): Magnesium plus Gallium yields a joke. Next comes the easy alphametic: Solve the answer to the bad ...
6
votes
1answer
164 views

Alfred E. Neuman alphametic

Every letter and every question mark stands for a digit in base-9 representation. Different letters stand for different digits. Leading digits are always non-zero. An alphametic for the lovers of ...
7
votes
3answers
211 views

Multiplicative alphametic: This is too hard

Every letter and every question mark stands for a digit in base-10 representation Different letters stand for different digits Question marks are placeholders and stand for arbitrary digits (that ...
0
votes
2answers
186 views

Simplist proof you have for the Monty Hall Problem [closed]

This sounds simple. What is the easiest solution to the Monty Hall problem you have which does not use listing out every probability and also requires you use algorithms? Also, no research or ...
9
votes
7answers
706 views

Recover book titles and suggest more books

I am working on a series of book-trivia puzzles. Given an excerpt from the book directly mentioning the book title, players are asked to fill in the title. Example Given the excerpt ...now we ...
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 ...
71
votes
2answers
6k views

Oh dang, I have to change my whole answer!

One day, you enter your math classroom. On the board, there are the words POP QUIZ. Dang it! Was it about fractions? you knew you were bad with fractions. You look down. $\begin{array}{|cc|} \...
6
votes
2answers
213 views

Square-root of CAREER alphametic

Every letter stands for a digit in base-10 representation, different letters stand for different digits, and leading digits are always non-zero. $\sqrt{CAREER} \,\, = \,\, RUT $ Which digit does ...
34
votes
11answers
8k views

Ten girls around a table

Ten girls are sitting around a table. Each of them picks a real number and whispers it to the two neighbors immediately to the left and to the right. (Hence: each girl communicates one number, and ...
6
votes
3answers
317 views

Flock of Geese alphametic

In each of the following three alphametic puzzles, every letter stands for a digit in base-10 representation, and different letters stand for different digits. Leading digits are always non-zero. <...
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 ...