# Questions tagged [no-computers]

A puzzle designed to be solved without using calculators, online decoders, or computer programming. Using a computer to type and post the answer is allowed; the spirit of this tag is to make people solve the puzzle on their own.

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### Puzzling rectangles [closed]

Can you find two unequal rectangles whose areas add to $5\sqrt5$? No computer solutions please.
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### Heteropalindromes in a Word Square

Say hello to a not-so-simple, 4x4 word square: This little monstrosity has two rules; to define the first rule, have you ever heard of a heteropalindrome? Strings of letters that form words when ...
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### How do I ring my friend's doorbell?

My friend, a curmudgeon who dislikes visitors, recently installed a puzzle-doorbell. It consists of ten push buttons in a row, labelled from left to right: ...
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### The Thieves and the Gold Bars

Two thieves (Rod and Lia) carry out a big heist and steal 16 gold bars. They get away in their car when they run into a bad accident and the car is completely wrecked. Luckily they survive with their ...
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### Most points on a circle

What is the most number of integer lattice points that lie on the circumference of a single circle whose radius is 80 or less? Please no computer computations.
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### Life, uh, Finds a Way

[Rated PG-13 for language} I saw someone wearing a "Life happens" t-shirt, which is a fine enough sentiment, but not the most common turn of phrase. It made me wonder... How fast can you ...
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1 vote
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### Self-indulgent numbers

Let's call a positive integer N self-indulgent of degree K>2 if for every positive integer k<K the following is true: More than half of the first k multiples N,2N,...,kN of N contain with ...
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### Manual tiling with 8 dodecadudes

Here are 8 dodecadudes. (Drawn from the very numerous dodecadrafters, made from 12 half equilateral triangles, dodecadudes are a subset of 770 pieces with sharp points and narrow necks excluded). ...
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### Split 1 through 6 into a product of 24 and sum of 12

How many ways are there to split the numbers 1, 2, 3, 4, 5, and 6 into two groups, such that the product of the numbers in one group is 24 and the sum of the numbers in the other group is 12? An ...
203 views

### Wormeus and the Stickotaur (maze 2)

Here is another Wormeus maze, following a previous puzzle that is yet to go viral. Wormeus has to eat all the apples without dying a horrible squishy death at the hands of the Pink Lady Stickotaur. I ...
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### Swapping 3 knights in a 4x4 grid

Can you swap black and white knights in this 4x4 grid? There is one important constraint: at no point can a knight be under attack by an opponent knight. Knights move using standard chess moves (L ...
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### Quartum non datur

Can you give a good rational approximation of $$\sqrt[3]2 \times \sqrt[4]2$$ without doing any significant maths? Hint: Attribution: Mine.
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### Wormeus and the Pink Lady Stickotaur

Wormeus lives in a labyrinth containing lots of apples. His main ambition in life is to eat as many apples as possible but his nemesis, the evil Pink Lady Stickotaur, has other ideas – if you pardon ...
• 7,434
694 views

### AnaCross: A crossword made of anagrams

This is a new type of puzzle I've devised: the AnaCross. Nothing new under the sun and all, I'm sure someone has made one before, but I've never seen it. The rules are pretty simple. At the end of ...
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### This ᴀɴᴅ That musical act from the past [closed]

Below is a fill-in-the-blanks three-part list of variously-venerable musical acts of the form “________ ᴀɴᴅ ʜɪs/ᴏᴜʀ/ᴛʜᴇ _________.” The example of “Paul Revere ᴀɴᴅ ᴛʜᴇ Raiders” has been filled in for ...
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### Probability of a successful DT Cannon

In multiplayer Tetris, there are a number of opening setups that let you send powerful attacks very quickly. One popular opening is the DT Cannon, which allows the player to very quickly send a T-Spin ...
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### Non-increasing arrangement

We are arranging the numbers from 1 to 8 in an order so that three consecutive terms cannot be increasing. For example, 12345678 isn’t allowed but 81436572 is. How many ways are there to do it? Please ...
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### Escape from Sudoku!

An entry in Fortnightly Topic Challenge #50: Escape Rooms I hesitated to enter this in the Escape Room FTC, but I definitely was inspired by the challenge to create this puzzle, and it is, in some ...
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### Find three ways of forming the number 100 using 3,3,5,7

As it says in the title. Rules: anything not explicitly allowed is forbidden. use 3, 3, 5, 7 and multiplication, division, sum, difference, unary minus, and exponentiation in any order. Parentheses ...
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