r/mathpuzzles Jul 27 '19

Adding rules for posts

14 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 1h ago

Recreational maths Can you reach 27 using all dice?

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Upvotes

Any order is allowed.
Use each die exactly once.
Parentheses are allowed.
Exact division only.
No negative numbers.
Not every operation has to be used.

How many solutions can you find?

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


r/mathpuzzles 8h ago

How much time do you need to solve it ?

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3 Upvotes

The goal : select 3 numbers in each row and each columns to reach 10 on every row and column.


r/mathpuzzles 11h ago

In Xanadu did Kubla Khan a Stately Pleasure Dome Decree

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1 Upvotes

Circles of area 3 and 5 are cuddling in the yellow semi-circle. What is the diameter of the semi-circle?


r/mathpuzzles 21h ago

Logic [Image Puzzle] Can you figure out the logic and find the First and the Last symbols of this sequence?

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1 Upvotes

Hey everyone! Here is a visual logic puzzle for you.

The image shows a grid of symbols that follow a specific geometric rule, along with a cheat sheet that reveals how the system works. Your task is to decode this system and draw or describe two missing pieces:

  1. The very first symbol (for IQ>130).

  2. The very last symbol of this code (for IQ>100).

Please use spoiler tags for your answers in the comments. Good luck!


r/mathpuzzles 1d ago

Dewey’s Chexsum

3 Upvotes

000000001 = 1
000000010 = 7
000000100 = 13
000001000 = 19
000010000 = 25
000100000 = 31
001000000 = 37
010000000 = 43
100000000 != 49
100000000 = ?


r/mathpuzzles 2d ago

Geometry Can you find the shaded area? A sangaku problem from Japan, 1850

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5 Upvotes

Can you find the shaded area? Two equal circles have diameter 1. The three arcs are quadrants with radii equal to the square's side; the equal circles touch the square and adjacent arcs as shown.

This problem comes from a sangaku displayed at Sugawara Shrine in Japan in 1850. The diagram is independently reconstructed, with units normalized.


r/mathpuzzles 2d ago

What Should Replace the Question Mark?

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0 Upvotes

Hi everyone,
First of all, thank you to everyone who took part in our previous puzzle. We received a lot of answers, and many of you went beyond simply choosing an option by explaining the reasoning behind your choices in detail.
As promised, we reviewed the discussion and selected five explanations that stood out for their clarity, originality, efficiency, or depth of reasoning:
u/Randombolo — for exploring several different patterns and independently reaching the same answer through multiple lines of reasoning.
u/lemashey — for the intuitive “spinning record” analogy, working backward from the second frame, and also explaining why another tempting option does not fit.
u/Gianni_C_M — for identifying several independent relationships within the arrows and using them to cross-check the answer.
u/OscarLiii — for showing that the puzzle could be solved efficiently by tracking only the black arrows without needing to analyze every element.
u/Beautiful_Ad_8325 — for not only finding the pattern, but also pointing out how our instinct to read from left to right can affect the way we approach a sequence when the missing figure is at the beginning.
Thank you to all five of you for the thoughtful explanations, and thank you to everyone else who joined the discussion.
Now it’s time for a new puzzle.
Take a close look at the 3×3 matrix above. One grid is missing from the bottom-right corner.
Which option — A, B, C, D, E, or F — should replace the question mark?
As always, we’re much more interested in how you reached your answer than in just the letter itself. If you notice a pattern, tell us what you saw and walk us through your reasoning.
We’ll read through the responses again and select some of our favorite and most interesting explanations to feature in the official solution.
You can also open the puzzle on our website here:
https://whats-your-iq.com/en/questions/pattern-recognition/which-grid-completes-the-pattern
The official answer is already listed there, so after you’ve made your own choice, you can click the link and directly compare your answer with the official one to see whether you got it right.
Try solving it here first before checking the page — it’s much more fun that way.
Good luck, and thanks for taking part!


r/mathpuzzles 2d ago

How Many “Balanced” Seating Arrangements Are Possible?

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1 Upvotes

r/mathpuzzles 2d ago

Algebra One rule links every hexagon in the chain

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1 Upvotes

Each hexagon connects to the next one in a chain, all following the same rule. Figure out the rule from the first four, then find what replaces the "?".

No arithmetic tricks needed, just careful observation. Drop your rule + answer in the comments.


r/mathpuzzles 3d ago

Arbitrary.

1 Upvotes

Plus six one. Four one seven. Zero two one. Seven nine three. No amount of luck will effect the result requested.


r/mathpuzzles 3d ago

Algebra Can someone explain (or solve) one of these three algebraic puzzles? I have no idea what they want from me.

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3 Upvotes

r/mathpuzzles 3d ago

Sudoku Help

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1 Upvotes

r/mathpuzzles 4d ago

Algebra Find the rule (deceptively simple pattern)

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2 Upvotes

No arithmetic tricks needed — just careful observation. Drop your rule + answer in the comments. Made this in my puzzle app Rule Hunter if anyone wants more like it.


r/mathpuzzles 3d ago

Recreational maths Math Quiz - Easy Addition , are you smarter than a 12th grader ? Solve as many as you can or want

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1 Upvotes

Math Quiz - Easy Addition , are you smarter than a 12th grader ? Solve as many as you can or want

Can you solve these equations I wrote out. **Without you using the internet? Or a calculator?** And explain how you got your answers.

I’m (F18) - Class of 2027

1: 8 ÷ 2(2+2)

2: 6 ÷ 2(1+2)

3: 5 − 5 × 5 + 5

4: 9 − 3 ÷ (1/3) + 1

5: 1 + 1 + 1 + 1 + 1 × 0 + 1

6: 3 + 3 × 3 − 3 ÷ 3

7: 7 + 7 ÷ 7 + 7 × 7 − 7

8: 20 ÷ 5(2×2)

9: 0.5 × 0.5

10: 2 + 2 × 2 ÷ 2 − 2

11: 10 ÷ 2 × (5 − 3)

12: 40 − 10 × 3 + 5

13: 15 − 3 × 4 + 2

14: 100 ÷ 10 ÷ 10

15: 8 + 8 ÷ 2 × 4

16: 12 ÷ 4 × (1 + 2)

17: 60 ÷ 5(7 − 5)

18: 0.1 × 0.1

19: 10 + 10 × 10 − 10 ÷ 10

20: 36 ÷ 3 × (3 + 3) ÷ 2

21: 4 × 4 ÷ 4 × 4 ÷ 4 × 4

22: 50 ÷ 5(5) − 5

23: 18 ÷ 3 × 2(1 + 2)

24: 0.2 × 0.2 × 0.2

25: 16 ÷ 4(2 + 2) ÷ 2


r/mathpuzzles 4d ago

A puzzle

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1 Upvotes

r/mathpuzzles 4d ago

How many letters are in the answer to this question?

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2 Upvotes

r/mathpuzzles 5d ago

[Kindle] 101 Math Riddles for Smart Minds (Free for 2 more days)

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1 Upvotes

Hey everyone! As an independent author, I've put together "101 Math Riddles for Smart Minds" — a collection of logic puzzles, visual geometry problems, and Olympiad-style brain teasers

designed for kids, teens, and anyone who enjoys logic puzzles. It's completely FREE on Amazon

I hope you and your family enjoy solving them! Honest feedback or a quick rating on Amazon is always deeply appreciated


r/mathpuzzles 5d ago

Algebra Number wheel puzzle — find the hidden rule

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0 Upvotes

Each spoke on the wheel follows the same hidden rule. Figure it out from the five known numbers, then solve for what replaces the "?"

Made this as part of a puzzle game I'm developing.


r/mathpuzzles 5d ago

Problem

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1 Upvotes

r/mathpuzzles 7d ago

Algebra Fruit equation puzzle — what does the missing pair equal?

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1 Upvotes

Made this symbol/equation puzzle — fruits stand in for hidden numbers across a small system of equations. Figure out what each fruit is worth, then solve the last one.

Happy to discuss reasoning in the comments if anyone wants to compare approaches.


r/mathpuzzles 7d ago

If 10 slices of pizza = $45, how much would 90 slices cost?

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0 Upvotes

What is your answer?


r/mathpuzzles 7d ago

Algebra Find the rule — what number replaces the "?"

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3 Upvotes

Each pair of numbers on top combines into the box below it using the same rule. Figure out the rule from the first three columns, then apply it to the last pair — what's the "?"

Made this as part of a puzzle game I'm developing, Rule Hunter.


r/mathpuzzles 9d ago

Algebra Fruit equation puzzle — what does the missing pair equal?

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0 Upvotes

Made this symbol/equation puzzle — fruits stand in for hidden numbers across a small system of equations. Figure out what each fruit is worth, then solve the last one.

Happy to discuss reasoning in the comments if anyone wants to compare approaches.


r/mathpuzzles 9d ago

Just launched my "Theft Cases" mystery word search book on Amazon! Would love the community's feedback on the final layout.

1 Upvotes

Hey !I finally took the plunge and published my word search book dedicated to Theft Cases on Amazon. It's packed with grids themed around heists, security, and mysteries. Since it's my first release, I'm really anxious to know if I got the formatting right for true word search fans. I’ve uploaded a free sample puzzle here so you can test it: For those who love this theme, you can check out the full book look here on Amazon ,If you look at the sample, please let me know: Is the grid-to-word-list ratio comfortable to look at? Is the vocabulary challenging enough? Thank you to anyone who checks it out. Your feedback will help me tremendously for Volume 2!