All Questions
Tagged with grid-deduction mathematics
73 questions
6
votes
1
answer
821
views
Fill the 4x4 grid with numbers to make eight arithmetic progressions
In the 4x4 grid below, fill each empty square with a number such that the numbers in each row form an arithmetic progression when read from left to right. Similarly, the numbers in each column form an ...
- 21.4k
7
votes
1
answer
606
views
Fill this Sudoku variant so that the sums of numbers in the outlined regions are all different
Place numbers in the grid so that each row and each column contain all the numbers {1,2,3,4,5} (each exactly once) and the sums of numbers in the outlined regions are all different.
Attribution: ...
- 21.4k
8
votes
3
answers
823
views
Fill the grid with numbers to make all four equations true
Using all the numbers {1,2,3,4,5,6,7,8}, each exactly once, fill each empty white square with a number so that all the horizontal and vertical equations are true. The grey squares are not used.
...
- 21.4k
4
votes
4
answers
886
views
Fill a grid with numbers so that each row/column calculation yields the same number
Using all the integers 1 through 9, each exactly once, put a number into each square in the grid below so that the result of each row and column calculation is 5.
All operations are performed "...
- 21.4k
16
votes
1
answer
879
views
Solid border Yin-Yang
Yin-Yang is a grid deduction puzzle with the following rules:
Fill each cell with either a black circle or a white circle.
All circles of a given color must form a single orthogonally-connected ...
- 3,503
10
votes
2
answers
629
views
Fill the triangular grid using the digits 1-9 subject to the constraints provided
Fill the grid using the digits 1-9 four times each. No row or column can contain the same digit more than once. The total of each row and column is provided, as well as clues to the numbers forming ...
- 21.4k
31
votes
1
answer
4k
views
Are you radical enough to solve this SURDOKU?
All "surds" represent whole numbers smaller than 15, and the same number is never used twice with the same index. (It's a sudoku.)
Attribution: PUZZLEBOMB.co.uk. Puzzles by @stecks & @...
- 21.4k
15
votes
4
answers
959
views
Fill the grid subject to product, sum and knight move constraints
Using the numbers 2, 3, 4, ... 19 each exactly once, fill some of the empty squares in the grid with a number so that the product of the numbers in each row is as shown, as is the sum of the numbers ...
- 21.4k
9
votes
2
answers
329
views
How do I constrain a puzzle and keep a singular solution?
I am tinkering with a puzzle framework that has the following rules:
In a 6x6 grid of squares, arrange 8 strips of connected squares such that there exists exactly one strip of every length (i.e. a ...
- 173
12
votes
2
answers
561
views
sums and differences in consecutive grid [closed]
Fill in each square of the grid with a number from $1$ to $16$,
using each number exactly once. Numbers at the left or top give
the largest sum of two numbers in that row or column. Numbers
at the ...
- 589
13
votes
1
answer
526
views
Happy and joyful 2024!
Fill each empty cell of the board on the left with a digit between 1 and 9. Each box and each column and row must contain all digits.
The dots outside the board on the right indicate how many cells in ...
- 2,155
0
votes
2
answers
432
views
A 4x4 sudoku shouldn't be that hard, right? Right?
Note: this is not in conjunction with my Minesweeper puzzles
Got this idea from one of Cracking the Cryptic's videos, I don't remember which one though. This exact puzzle is still overall unique.
...
- 2,809
7
votes
1
answer
266
views
Intermingled primes
This puzzle is part of the Monthly Topic Challenge #14: Think inside the (very small) box!.
6 different, 3 digit primes are stacked here in two layers.
You only see the sum of overlapping digits.
...
- 10.1k
15
votes
1
answer
1k
views
Trust me: you do not want to go down this road with me
Every cell has a digit from 0 to 9 or one of the four operation symbols +, −, ×, and /, signifying addition, subtraction, multiplication, and division respectively.
No digit appears more than once in ...
- 13.3k
8
votes
2
answers
614
views
How many Nonconsecutive Sudoku solutions are there?
Consecutive Sudoku is a variant with the additional rule that orthogonally adjacent numbers are consecutive if and only if there is a dot/bar on the line between them. A Nonconsecutive Sudoku is one ...
- 10.6k
3
votes
2
answers
470
views
Stuck on hard Kakuro
I‘m stuck on this Kakuro. Does anyone have any hints how to proceed? Thanks!
- 31
11
votes
1
answer
891
views
2
votes
1
answer
387
views
Honeycomb puzzle with hexagons [closed]
Can you place the numbers 1 through 9 in the honeycomb so that the sum of the numbers in the adjacent hexagons is a multiple of the number in the hexagons? This must be true in all hexagons.
The top ...
7
votes
2
answers
555
views
How to prove Yin-Yang alternating 2 by 2 is not allowed
Yin-Yang is a puzzle where one needs to fill each cells with either black circle or white circle following these rules:
Each color's circles must be connected to one another according to four-way ...
- 71
4
votes
2
answers
841
views
Tic-Tac-Collatz
Have you ever heard of the Collatz conjecture? Just in case you haven't, I'll summarize it for you! Take any positive integer $n$, if it is even then simply divide it by $2$; however, if it is odd, ...
- 10.6k
7
votes
1
answer
1k
views
Binary Sudoku Puzzle
The rules of Binary Sudoku are quite simple. It is very similar to regular Sudoku, except here we try to fill a 9x9 board with only black and white tiles following the below rules:
Every row, column, ...
- 81
4
votes
3
answers
2k
views
Finding a Kakuro trick
The following screenshot is taken from the Android app Kakuro++ (level 9 riddle 12)
And I verified the current status within the app. I managed to solve the puzzle by guessing a 50/50-number and ...
- 642
8
votes
3
answers
365
views
Place digits from 1 to 7 into each row and each column of the grid once. Numbers in the circles give the product of the four surrounding digits
What is the way to resolve the following puzzle?
Link to source. It's from a taiwanese math olympiad held in 2005.
- 81
16
votes
2
answers
1k
views
The Golden Age of Sudoku
Rules:
Each cell contains one of the following symbols: A23456789TJQK. No two cells in the same row or column have the same symbol.
The grid is divided into 11 square regions of different sizes. A ...
- 7,862
3
votes
1
answer
209
views
Let's settle our differences
Can you complete this grid and expose the existing relationships? There are no complex operations (e.g. no exponents, square roots, functions, etc), additionally the numbers are all natural numbers ...
- 10.6k
8
votes
1
answer
737
views
Can you reactivate a 4x4 Magic Square?
We've already removed the magic from a 3x3 magic square. Recently, one of our 4x4 magic squares was scrambled in an earthquake and I need your help to reactivate it's magic:
Objective
Your objective ...
- 10.6k
3
votes
2
answers
1k
views
Fix this puzzle, please!
My students claim that this disconnect four puzzle (fill the grid with crosses and zeros, such that no four equal symbols appear in a row. Rows can be horizontal, vertical, or diagonal) does not have ...
- 19.2k
11
votes
1
answer
247
views
Tiling three pears with three-pair hexominos
The 21 hexominos below are all those that can be made by joining three dominos together (i.e. they have a perfect matching with respect to the graph of their squares) and are not rectangles. The ...
- 8,805
7
votes
1
answer
351
views
Existence of index-uniform Hashi puzzles
On the left, we have a starting configuration for a game of Hashi, and on the right, its solution:
That is to say, the goal is to make connections (planar, and traveling only in cardinal directions) ...
- 2,419
2
votes
5
answers
876
views
Can you fill the cells by integers? [duplicate]
Can you fill the cells with integers so that all the equalities must be true?
- 1,703
7
votes
1
answer
336
views
A 3x3 grid with common factors
A $3 \times 3$ grid $G$ is filled with every number from the set $\{2,3,5,6,7,11,14,15,30\}$. Now a new $3 \times 3$ grid $H$ is formed, such that $H_{ij}$ is the number of neighbors of $G_{ij}$ that ...
- 37.6k
10
votes
4
answers
1k
views
Deriving a 3x3 grid from another one
A $3 \times 3$ grid $G$ is filled with every number from $1$ to $9$. Now a new $3 \times 3$ grid $H$ is formed, such that $H_{ij}$ is the number of neighbors of $G_{ij}$ that are greater than $G_{ij}$....
- 37.6k
37
votes
4
answers
2k
views
Self-contained math crossword with if-then-else clues
An entry in Fortnightly Topic Challenge #43: Variety Crossword Grids
Since I'm not good with with words and crosswords, here is a math crosswords: to know all the operands for the calculations you ...
- 5,162
25
votes
3
answers
2k
views
Ever heard of a W-Sudoku?
You may have heard of a type of Sudoku called an XV-Sudoku. In such a Sudoku, cells connected with an "X" must sum to 10 and cells connected with a "V" must sum to 5. In this W-...
- 8,890
1
vote
0
answers
453
views
Not a sudoku, but still fun?
Context:
I was trying to solve some of the puzzles on this site, when it occurred to me to make a puzzle variant myself.
I immediately could construct one with my additional rule. Making an ...
- 10.1k
2
votes
0
answers
527
views
A robot moving on a grid. Part 2
This is an extension of the discussion
A robot is placed on a grid point. At each move the robot must take three steps along the edge of the grid. After each step the robot must turn right. Lengths of ...
- 1,703
5
votes
3
answers
872
views
Will you be the first to get free?
It is your first day in prison and you are approached by a guard having a hunch for puzzles.
He tells you that he gives every new prisoner the chance to be freed if they can present him with a version ...
- 311
31
votes
7
answers
5k
views
Almost impossible Sudoku like puzzle
I was set a puzzle in my math class. I tried to do it using an equation but it didn't work it looked like a trial and error puzzle so I took it into school and the math teachers couldn't solve it.
Is ...
- 431
7
votes
2
answers
305
views
Another follow the path of relation through the grid
Inspired by Galen's series of puzzles...there is a relation between rectilinear-adjacent squares such that there is a unique rectilinear path from the top-left corner of the grid down to the bottom-...
- 29.2k
4
votes
1
answer
151
views
Follow the path of relation through the grid #9
There is a relation between rectilinear-adjacent squares such that there is a unique rectilinear path from the top-left corner of the grid down to the bottom-right corner of the grid. Each square can ...
- 2,296
3
votes
1
answer
161
views
Follow the path of relation through the grid #8
There is a relation between rectilinear-adjacent squares such that there is a unique rectilinear path from the top-left corner of the grid down to the bottom-right corner of the grid. Each square can ...
- 2,296
4
votes
1
answer
218
views
Follow the path of relation through the grid #7
There is a relation between rectilinear-adjacent squares such that there is a unique rectilinear path from the top-left corner of the grid down to the bottom-right corner of the grid. Each square can ...
- 2,296
5
votes
1
answer
157
views
Follow the path of relation through the grid #6
There is a relation between rectilinear-adjacent squares such that there is a unique rectilinear path from the top-left corner of the grid down to the bottom-right corner of the grid. Each square can ...
- 2,296
5
votes
2
answers
239
views
Follow the path of relation through the grid #5
There is a relation between rectilinear-adjacent squares such that there is a unique rectilinear path from the top-left corner of the grid down to the bottom-right corner of the grid. Each square can ...
- 2,296
3
votes
1
answer
172
views
Follow the path of relation through the grid #4
There is a relation between rectilinear-adjacent squares such that there is a unique rectilinear path from the top-left corner of the grid down to the bottom-right corner of the grid. Each square can ...
- 2,296
6
votes
1
answer
230
views
Follow the path of relation through the grid #3
There is a relation between rectilinear-adjacent squares such that there is a unique rectilinear path from the top-left corner of the grid down to the bottom-right corner of the grid. Each square can ...
- 2,296
7
votes
1
answer
282
views
Follow the path of relation through the grid #2
There is a relation between rectilinear-adjacent squares such that there is a unique rectilinear path from the top-left corner of the grid down to the bottom-right corner of the grid. Each square can ...
- 2,296
12
votes
1
answer
374
views
Follow the path of relation through the grid #1
There is a relation between rectilinear-adjacent squares such that there is a unique rectilinear path from the top-left corner of the grid down to the bottom-right corner of the grid. Each square can ...
- 2,296
4
votes
2
answers
313
views
How to solve the puzzle below?
Someone send me a puzzle in Discord and the creator said you can ask other people to help me solve. Here is one of the problems I can't solve.
Could anyone help me? It is hard!
- 6,334
4
votes
1
answer
225
views
Damaged 4x4 grid
John had a great party yesterday ; but he had a very important piece of paper in his pocket, and an unidentified liquid damaged it. One third of the information is lost. It looks like this now :
The ...
- 1,096