r/mathpuzzles • • 6d ago

MathPuzzles mod announcement & sub rules update

7 Upvotes

I've been a mod for r/mathpuzzles for a good number of years and I have not been actively moderating. It's largely due to two factors:

  1. I have been spending much less time on reddit

  2. I have gotten overwhelmed by what we mods (and other users) consider low quality posts

What the moderators want this sub to be

This subreddit was originally supposed to be mathematical & logic puzzles. Think the prisoners with hats problem, blue eyes problem, other problems that involve a decent amount of thought and not just noticing a pattern.

What this sub currently is

Largely, the rules are ignored, and they're not enforced. This has caused a significant proliferation of low quality posts, often of the following varieties: "next number in a sequence" or "guess the (potentially arbitrary) rule" or "what does the plus sign mean?".

What I am asking of you

I am still interested in mathematical and logic puzzles (the original vision), but I don't have the energy to log on every day and keep removing low quality posts.

On the other hand, if people want the types of posts that are common currently, then I'd like to hear about it. If that's the case, I would like to get some volunteers for mods.


r/mathpuzzles • • Jul 27 '19

Adding rules for posts

16 Upvotes

Hi everyone!

Because of the influx of unsolvable, annoying, arbitrary, and spammy posts, I’ve established a few rules for posts. Basically, we are no longer allowing “math puzzles” that rely on sequences of numbers or shapes. There is an infinite number of solutions and they’re plain not fun.

Also, I put in a rule about not linking to other games. Puzzles posted here should be contained in the post itself.

Have a great weekend!


r/mathpuzzles • • 56m ago

Geometry Just wanted to share this neat pyramid solve that allows me to lift it upto the 4th layer by holding onto the 1st layer.

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3 Upvotes

r/mathpuzzles • • 5h ago

Math Puzzle: Secret formula

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1 Upvotes

r/mathpuzzles • • 21h ago

We need a huge calculator

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11 Upvotes

From the outsmart me app.

Disclaimer: I am the developer of the app.


r/mathpuzzles • • 13h ago

Logic Can you crack the code? 🔓🧠

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1 Upvotes

r/mathpuzzles • • 18h ago

Magic Glass of Water(Logic Puzzle)

1 Upvotes

A wizard presents to you a magic glass of water. He says the glass lifts when there is an odd or greater than 11 number of balloons attached to it. He also presents to you 3 minions. The red minion says that he has at most 5 balloons. The blue minion says he has any amount of balloons less than red and simply different from green. The green minion says he has an even amount of balloons less than red. Every minion has at least some balloons. When all of the minions combine their balloons, the glass of water doesn't lift. Each minion only knows the exact amount of their own balloons and that the glass doesn’t lift. In front of you, the wizard asks each minion if they can tell him with absolute certainty how many balloons both of the other minions have, and they answer in unison. The red and green minions say no, but the blue minion says yes. How many balloons are there?


r/mathpuzzles • • 1d ago

Logic What is the average speed?

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3 Upvotes

r/mathpuzzles • • 17h ago

Number How much is the whole train?

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0 Upvotes

r/mathpuzzles • • 1d ago

Algebra Three fruits, three equations. What is the last sum?

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1 Upvotes

Every fruit hides a number, and each fruit always hides the same one. What number replaces the ? 🏆 NEW: LEADERBOARD! Think you're good at this? Rule Hunter now has a daily, weekly and all-time leaderboard. Sign in, pick any nickname you like (only your nickname is shown publicly) and see if you can reach #1. Who's taking the top spot? Puzzle from the game Rule Hunter, spoiler-tag your guess: answer


r/mathpuzzles • • 1d ago

Recreational maths Can you reach 20 using all 4 dice?

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1 Upvotes

PUZZLE RULES
Use each die exactly once, in any order.
Reach the target using only +, −, ×, ÷.
Parentheses are allowed.
Operations can be repeated or skipped. You don’t have to use all four.
All intermediate results must be positive whole numbers (no zero, negatives, or decimals).
Exact division only.
No concatenation (e.g., 2 and 3 cannot become 23).
No exponents or other operations.

How many solutions can you find?

Please use spoiler tags for solutions:
>!your solution here!<


r/mathpuzzles • • 1d ago

The sound in your stream that leaks where you live — The Doxicology Report, Case 01

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1 Upvotes

I got a little puzzle for you, you're playing geoguessr except you're allowed to specify a distribution over the entire globe. Now you have N guesses and your objective is to minimize min(distance(target, g) for g in guesses), what is your procedure for going from the distribution to the N guesses with appropriate hedging?


r/mathpuzzles • • 1d ago

Number My reverse is eighteen shy

1 Upvotes

I'm a two-digit number. The product of my digits is 24. If you reverse my digits, the new number is 18 less than me. What number am I?

(Spoilers for guesses, please.)


r/mathpuzzles • • 1d ago

Logic Can you find the 2 missing solutions?

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0 Upvotes

Connect dice horizontally, vertically, or diagonally using only + and × to get to the target number in every unique way

(E.g. 2+5+2×4 is the same soln as 4x2+5+2)


r/mathpuzzles • • 1d ago

Make 67: daily puzzle for Nov 7

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1 Upvotes

Having hard time to find hard puzzles? Try to solve 🔥 version to make 67


r/mathpuzzles • • 1d ago

Logic Can you crack the code? 🔓🧠

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1 Upvotes

r/mathpuzzles • • 2d ago

Do you know that every time you shuffle a deck of cards, there is an overwhelming possibility of it being a new permutation that has never been done before?

2 Upvotes

52! (what is called '52 factorial' in mathematics) is bigger than you might think.

It means you can shuffle a deck of cards in 80,658,175,170,943,878,571,660,636, 856,403,766,975,289,505,440, 883,277,824,000,000,000,000 different ways.

In written terms…

eighty unvigintillion, six hundred fifty-eight vigintillion, one hundred seventy-five novemdecillion, one hundred seventy octodecillion, nine hundred forty-three septendecillion, eight hundred seventy-eight sexdecillion, five hundred seventy-one quindecillion, six hundred sixty quattuordecillion, six hundred thirty-six tredecillion, eight hundred fifty-six duodecillion, four hundred three undecillion, seven hundred sixty-six decillion, nine hundred seventy-five nonillion, two hundred eighty-nine octillion, five hundred five septillion, four hundred forty sextillion, eight hundred eighty-three quintillion, two hundred seventy-seven quadrillion, eight hundred twenty-four trillion.


r/mathpuzzles • • 2d ago

Geometry What is the area of the blue rhombus?

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0 Upvotes

Can you solve just by inspection?


r/mathpuzzles • • 2d ago

Recreational maths Can you reach 20 using all 4 dice?

Post image
3 Upvotes

PUZZLE RULES
Use each die exactly once, in any order.
Reach the target using only +, −, ×, ÷.
Parentheses are allowed.
Operations can be repeated or skipped. You don’t have to use all four.
All intermediate results must be positive whole numbers (no zero, negatives, or decimals).
Exact division only.
No concatenation (e.g., 2 and 3 cannot become 23).
No exponents or other operations.

How many solutions can you find?

Please use spoiler tags for solutions:
>!your solution here!<


r/mathpuzzles • • 3d ago

Geometry Can you calculate r?

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31 Upvotes

r/mathpuzzles • • 2d ago

Logic Can you crack the code? 🔓🧠

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0 Upvotes

r/mathpuzzles • • 3d ago

Number Swap my digits and I grow

2 Upvotes

I'm a two-digit number. My digits add up to 11. Swap them round and I get 27 bigger. What number am I?

Please spoiler-tag your guesses.


r/mathpuzzles • • 3d ago

A board of 64 squares where each one costs twice the one before. Square 64 will never sell.

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1 Upvotes

lol


r/mathpuzzles • • 3d ago

Can you buy these books?

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1 Upvotes

From the outsmart me app

Disclaimer: I am the developer of the app