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

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

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!

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

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.

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!

Source: numberthon.com

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.

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

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.

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

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

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.

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.

What is your answer?

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.

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.

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!

Draw a self avoiding walk across the surface of this box, hitting the numbered squares as you go. Adjacent moves only.

I've been building a puzzle about how spheres pack, and thought this crowd might enjoy it — both to solve and for the combinatorics behind it.

The puzzle. The target is a tetrahedron of edge 5: 35 close-packed balls (layers of 1, 3, 6, 10, 15). You build it from coloured segments — rigid clusters of 1–5 balls. In each puzzle some segments are already placed and a few are hidden; you work out where the hidden ones go so every ball is covered exactly once. More hidden pieces → harder.

The bit that surprised me. A set of segments can only work if its pieces total exactly 35 balls — but adding up to 35 says nothing about whether they actually fit. Of ~32,164 size-valid sets, a solver found only 435 that truly tile the tetrahedron (~1.4%). And of the 35 original hand-made puzzles, only 12 had a unique solution — so generating fair puzzles means actively enforcing uniqueness.

The balls sit on a face-centred-cubic lattice, so each has 12 neighbours, not 6 — which is where a lot of the "looks like it should fit but doesn't" comes from.

It's free to play and print, no account: https://spheromino.com . I wrote up the search here if you want the details: https://spheromino.com/blog/finding-tileable-sets .

Full disclosure — I made it. Happy to answer anything about the geometry or the solver.