Questions tagged [no-computers]

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

4
votes
2answers
249 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
823 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
154 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
108 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
765 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
146 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
188 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
244 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
171 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
395 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
175 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
660 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
135 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
949 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
159 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
204 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
184 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
695 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 ...
14
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 ...
70
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
204 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
310 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 ...
5
votes
3answers
205 views

French alphametic (corrected)

This is the corrected version of puzzle French alphametic (misspelled) Every letter stands for a digit in base-10 representation, different letters stand for different digits, and the four ...
0
votes
2answers
265 views

French alphametic (misspelled)

The following puzzle has a spelling mistake: DOUCE should be DOUZE. The correct version is: French alphametic (corrected) (Surprisingly the faulty version allows feasible solutions.) Every ...
4
votes
2answers
206 views

Neil Armstrong and Buzz Aldrin alphametic

Every letter stands for a digit in decimal representation, different letters stand for different digits: MEN + CAN = REACH - MOON Which digit does each ...
8
votes
2answers
189 views

Nebulosity alphametic

Every letter stands for a digit in decimal representation, different letters stand for different digits: ...
6
votes
1answer
154 views

Wheat field alphametic

Every letter stands for a digit in base-11 representation, different letters stand for different digits: WHEAT + FIELD ------------ FARMER ...
9
votes
2answers
252 views

Happy days alphametic

Every letter a decimal digit, different letters for different digits: HAPPY HAPPY HAPPY + DAYS ---------- AHEAD Which digit does each letter ...
6
votes
3answers
831 views

Baseball games alphametic

Every letter a decimal digit, different letters for different digits: BASE + BALL -------- GAMES Which digit does each letter represent?
15
votes
4answers
387 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 ...
5
votes
2answers
701 views

I Was Told It Would Explode

Story: There is a line of bombs, all over a building. You are the bomb defusal expert, and you are the one everyone is counting on the save the city, for as if any one of the bombs go off, you, and ...
5
votes
1answer
205 views

Crossing out a digit

Find the largest integer $N$ whose decimal representation has the following properties: The rightmost digit in the decimal representation is not $0$. There exists a digit $d$ in the decimal ...
-13
votes
1answer
501 views

Social networking “party” system

A party is a group chat, the only difference being there's a "leader" (this is the person who started the chat) In these parties, there can only be 5 maximum users, this includes the leader. In ...
4
votes
1answer
153 views

Increasing rows and columns

Cosmo has arranged the integers $1,2,\ldots,49$ in a $7\times7$ table, so that in each row (left to right) and in each column (top to bottom) the entries occur in increasing order. Questions: ...
10
votes
4answers
2k views

A sloppy calculation

Little Johnny Red forgot to write the multiplication sign between two 3-digit numbers $x$ and $y$ and simply wrote them as one number. When Johnny's teacher graded the homework, it turned out that the ...
-10
votes
2answers
477 views

Longest $Scramble Sentence$? [closed]

Before we begin, allow me to define what I call a Scramble Sentence, A Scramble Sentence is a grammatically correct sentence, where at least 1 other permutation, of the letters in the sentence, ...
34
votes
1answer
2k views

Can you stop the rambling rook?

This is a chess puzzle someone showed me a long time ago. If you already know this puzzle please give the others a chance to solve it first. Above you see a position where white is obviously on the ...
8
votes
6answers
633 views

What is the Key to Good No-Computers Puzzles?

Question What advice, strategies, keys, or elements would you suggest for creating challenging puzzles that aren't (reasonably) computer soluble? Details I'm a programmer, so I can appreciate the ...
4
votes
7answers
4k views

Find the longest string of words such that the (4 letter) end of one word is the start of the next

Here is an open-ended challenge. Find the longest series of English words such that the final four letters of word $n$ are the same as the first four letters of word $n+1$. Example (3 words) ...
6
votes
1answer
720 views

A Four Liner of my Own: I'm counting on you

With all the popularity of four liners lately, I figured I'd contribute. Since my recent riddles seem to have been too hard, I'll err on the side of ease this time. Determine what each line is ...
11
votes
1answer
3k views

Two dead beans on a stone

Samuel Bean, a Canadian doctor, had a tombstone erected in Rushes Cemetery near Crosshill, Wellesley Township, Ontario, for his first two wives, Henrietta and Susanna. The original stone was carved in ...
8
votes
2answers
957 views

The magic of the primes

A mathematician, a physicist, and an engineer found themselves caught in an ancient anecdote. Lacking a chemist to brew them an anecdote antidote, they fell to arguing over which of them was to be the ...
7
votes
4answers
1k views

Comparing exponents - no computers!

Which is larger, $99^{100}$ or $100^{99}$? Which is larger, $999^{1000}$ or $1000^{999}$? Or more generally, for $n$ any natural number: which is larger, $n^{n+1}$ or $(n+1)^n$? Please do not use a ...
4
votes
3answers
2k views

How is it possible?

I have been captured, then shot, framed and hung. But luckily, I am not dead. How is it possible? Disclaimer: this puzzle is inspired by real world observation, so no alien lifeforms, super heroes ...
16
votes
1answer
693 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. ...