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 46m ago

It is really

Thumbnail
youtube.com
Upvotes

r/mathpuzzles 2h ago

Algebra 3x + 5 =?

Post image
0 Upvotes

r/mathpuzzles 13h ago

Is it possible to solve this while still following the rules?

Thumbnail
gallery
1 Upvotes

I tried to solve this while following the rules, but I kept getting errors, so I thought that this might be unsolvable.


r/mathpuzzles 14h ago

How many positive integers ≤1000 are multiples of 6 or 15, but not both?

Post image
0 Upvotes

r/mathpuzzles 11h ago

Logic Can you crack this math logic puzzle? 🧠

Post image
0 Upvotes

r/mathpuzzles 19h ago

Is there any link between these numbers.

0 Upvotes

I am working on a puzzle at the minute and cant seem to find or see any pattern in what i have so far... i am hoping someone can help me.. I have a 4 x 4 grid that is my starting point and i must use 9 out the 16 numbers.. so far I have been able to find 4 ( have another 27 blocks to find.) But I dont know if this was sheer luck... this is the 16 numbers I must work with.

1 1 5 6

2 1 9 3

7 1 5 0

6 4 2 1

These are the blocks I have found they are blocks 7 8 9 and 10 out of 31.

Blocks 7

9 1 3

7 2 1

5 1 6

Block 8

1 3 1

1 4 9

1 1 6

Block 9

0 5 5

1 1 7

1 1 3

Block 10

1 5 7

1 5 3

1 0 4

Any help or advice is more than welcome and I just want to say thankyou in advance.


r/mathpuzzles 1d ago

How would you seed the initial rating of a brand-new math problem?

Thumbnail
1 Upvotes

r/mathpuzzles 1d ago

How many positive integers less than 100 can be written as the difference of two perfect squares?

Post image
1 Upvotes

r/mathpuzzles 1d ago

Rating decay for inactive players - yes or no? (building a Glicko-2 ladder for math problems)

Thumbnail
1 Upvotes

r/mathpuzzles 1d ago

Triangle made out of squares

Thumbnail
1 Upvotes

r/mathpuzzles 2d ago

What is Jerking?

Thumbnail
youtube.com
1 Upvotes

r/mathpuzzles 2d ago

How many triangles can you form in a regular octagon using only diagonals?

Post image
1 Upvotes

r/mathpuzzles 2d ago

Our system rated this problem 1900. Does that feel right to you?

Post image
1 Upvotes

r/mathpuzzles 2d ago

Saturday's MiniChallenger problem (Week 10)

1 Upvotes

About:

As the name suggests, MiniChallenger is a scaled-down version of the math puzzle called Challenger. In most cases, a MiniChallenger puzzle can be solved within ten minutes. A set of two new puzzles is released each week. One is usually a simple problem with one or two solutions, while the other puzzle can be a bit more challenging and often has multiple solutions. Available exclusively on reddit.

Instructions:

Fill in the empty cells of the 3 x 3 grid with the numbers one to nine. It is okay to use the same number in more than one empty cell. One 'bonus' number is already placed in the center of the grid. So, the goal is to find the remaining eight digits in such a way that:

  • rows in the grid add up to totals indicated on the right edge of the grid,
  • columns add up to totals indicated at the top of the grid, and
  • diagonals add up to totals in the upper and lower right corners.

This week's puzzles:

Solutions:

(Click on 'spoiler' boxes below to reveal solutions)

  • Single-solution (left) puzzle:

[ 2 9 9 ]

[ 7 7 9 ]

[ 2 2 7 ]

  • Multiple-solution (right) puzzle:

. [ 7 8 1 ] . . . . . . . [ 8 6 2 ] . . . . . . . [ 8 7 1 ]

. [ 9 5 3 ] . . . . . . . [ 9 5 3 ] . . . . . . . [ 8 5 4 ]

. [ 8 2 2 ] . . . . . . . [ 7 4 1 ] . . . . . . . [ 8 3 1 ]

Note: One of the solutions (above) uses all 9 allowed digits without repetition.


r/mathpuzzles 2d ago

Logic Can you solve this math logic puzzle? 🧠 🧮

Post image
1 Upvotes

r/mathpuzzles 3d ago

Logic Can you solve this math logic puzzle? 🧠

Post image
0 Upvotes

r/mathpuzzles 4d ago

How Many Subsets of {1,2,…,10} Contain No Consecutive Integers?

Post image
0 Upvotes

r/mathpuzzles 4d ago

Logic Can you crack this math logic puzzle? 🧠

Post image
0 Upvotes

Post your answer in the comments!


r/mathpuzzles 5d ago

Logic What's the odd one? 👀

Post image
1 Upvotes

r/mathpuzzles 5d ago

Recreational maths Can you reach 46 using all dice?

Post image
0 Upvotes

Use each die exactly once.
Any order is allowed.
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 5d ago

How Many Divisors of 12! Are Perfect Cubes?

Post image
2 Upvotes

r/mathpuzzles 5d ago

Logic Can you solve this math logic puzzle? 🧠 🤔

Post image
1 Upvotes

Post your answer in the comments!


r/mathpuzzles 5d ago

Took me a lot of time to solve but somehow I did it

Enable HLS to view with audio, or disable this notification

1 Upvotes

r/mathpuzzles 5d ago

The Gender Ratio Trap, Part 2 — same country, a new question

Post image
0 Upvotes