Questions tagged [logical-deduction]

A puzzle that requires formal logical deduction to arrive at the solution. This suggests more than merely reasoning through clues to find an answer (you might want [situation] for that).

Filter by
Sorted by
Tagged with
3
votes
1answer
36 views

A Final Digitial Sudoku! - SS#14

An entry in Fortnightly Topic Challenge #47: "Wacky Sudokus" Other puzzles in this series Welcome to the final puzzle in this series! For more information about the series, see the first ...
9
votes
2answers
167 views

Unequal Curfew - Donut Hole

This is a Curfew variant. Curfew is a genre invented by Hempuli; I made a slight modification to give this variant. Rules of Unequal Curfew: Draw a loop that visits every circle. Each visit to a room ...
14
votes
1answer
279 views

This Sudoku Park iS LIT!

An entry in Fortnightly Topic Challenge #47: "Wacky Sudokus" The grid below is a normal Sudoku grid with normal Sudoku clues, but the completed grid also houses a Statue Park! The completed ...
12
votes
1answer
235 views

Sudoku: Odd Bonds

An entry in Fortnightly Topic Challenge #47: Wacky Sudokus. Edit: Clarified three of the rules. Rules: Normal sudoku rules apply. Inside the sudoku, there exists one "loop". The loop ...
9
votes
1answer
200 views

A Fractal Sudoku - SS#13

An entry in Fortnightly Topic Challenge #47: "Wacky Sudokus" Other puzzles in this series Welcome to the penultimate puzzle in this series! For more information about the series, see the ...
6
votes
1answer
147 views

Logic grid puzzle - Carson City Chronicle

I can't figure this one out. Any help would be appreciated. Journalist-in-training Janet Seymour's byline appeared in the Carson City Chronicle on six days last week. On each day (Monday through ...
9
votes
1answer
418 views

Sudoku with no grid and no numbers!!? - SS#12

An entry in Fortnightly Topic Challenge #47: "Wacky Sudokus" Other puzzles in this series Welcome to the twelfth puzzle in this series! For more information about the series, see the first ...
20
votes
1answer
887 views

Sudoku in Technicolor!

An entry in Fortnightly Topic Challenge #47: "Wacky Sudokus" This puzzle consists of three overlapping Sudokus, coloured red, blue and green, so each cell will contain three digits, one of ...
15
votes
2answers
2k views

Hotaru Beam Puzzle: Is it impossible?

I saw this puzzle on Twitter by user @lilva_0419 and I personally feel that it is impossible to solve. Can you prove me wrong (or right)? Source on Twitter Try it online Rules (see Wikipedia): ...
6
votes
1answer
616 views

Finding the median of 5 numbers

There are 5 boxes labeled A, B, C, D and E. Each box contains a distinct number, but you don't know what it is. You can select three boxes and the Oracle will tell you which box contains the median* ...
6
votes
3answers
523 views

Table of mathematical expressions - fill in 1-9

Fill in the numbers 1 through 9 in the 9 empty cells (each number appears exactly once) to make the row and column expressions equal to the number at the end of the row or column. Regular math ...
7
votes
1answer
88 views

This Sudoku takes a step up! - SS#11

An entry in Fortnightly Topic Challenge #47: "Wacky Sudokus" Other puzzles in this series Welcome to the eleventh puzzle in this series! For more information about the series, see the first ...
-4
votes
0answers
61 views

How to get the least amount of pours to obtain a fractional amount of yoghurt?

The puzzle is as follows: A dairy plant in Milwaukee is well known for its yoghurt. However during the quality control a factory worker forgot to bring a set of adequate vessels to measure the ...
37
votes
1answer
1k views

Didn't you ask me for a crossword?

An entry in Fortnightly Topic Challenge #forty-seven: "Wacky Sudokus" Here's that crossword you asked for... Sorry, what's that - you didn't ask me for a crossword?? TASK: Solve the puzzle ...
12
votes
1answer
344 views
+100

Skyscrapers in Sudoku!!! - SS#10

An entry in Fortnightly Topic Challenge #47: "Wacky Sudokus" Other puzzles in this series Welcome to the tenth puzzle in this series! For more information about the series, see the first ...
15
votes
1answer
455 views

Chain Puzzle: Video Games #01 - Teleporting Crosswords!

This is the first Chain Puzzle in the Video Games series, in which all puzzles are themed around video games of all genres. The answer to this puzzle is a thematic word or phrase. The solver whose ...
24
votes
1answer
1k views

A Puzzling Sudoku (Warning: Hot!)

An entry in Fortnightly Topic Challenge #47: "Wacky Sudokus" A Sudoku with an oddly familiar shape. Here's a Penpa Link. Rules: Normal Sudoku rules apply (Special) Thermometers: The ...
9
votes
1answer
284 views

A 7x7 Suguru - SS#9

An entry in Fortnightly Topic Challenge #47: "Wacky Sudokus" Other puzzles in this series Welcome to the ninth puzzle in this series! For more information about the series, see the first ...
10
votes
1answer
345 views

Nurikabe: The Super-Kabe Attacks!

This puzzle is another Nurikabe, but with a new twist for me: it's a gigantic Super-Kabe! It's also, in my opinion, quite tricky and has some interesting deductions. I hope you enjoy! Rules of a ...
25
votes
1answer
1k views

The Blank Sudoku

An entry in Fortnightly Topic Challenge #47: "Wacky Sudokus" (h/t to Beastly Gerbil, whose 1,2,3... Trinary!!! puzzle provided inspiration for this puzzle) This puzzle is a normal Sudoku, ...
11
votes
1answer
452 views

A Difficult Wacky Sudoku - SS#8

An entry in Fortnightly Topic Challenge #47: "Wacky Sudokus" Other puzzles in this series Welcome to the eighth puzzle in this series! For more information about the series, see the first ...
12
votes
1answer
222 views

A Scrumptious Sudoku Sandwich - SS#7

An entry in Fortnightly Topic Challenge #47: "Wacky Sudokus" Other puzzles in this series Welcome to the seventh puzzle in this series! For more information about the series, see the first ...
11
votes
1answer
271 views

Sudoku… with 10 digits? SS#6

An entry in Fortnightly Topic Challenge #47: "Wacky Sudokus" Other puzzles in this series Welcome to the sixth puzzle in this series! For more information about the series, see the first ...
18
votes
1answer
241 views

Compoundoku wants REALLY BIG and WACKY!

This is an entry for Fortnightly Topic Challenge #47: Wacky Sudokus. Rules of Compoundoku: Solve both left and right Sudokus. In addition, the board below them is the Compound Board of both Sudokus. ...
10
votes
1answer
302 views

Nurikabe: The Twisty Corridors

This puzzle is a Nurikabe. It is a little tougher than my previous one, which was designed for newer solvers, and it has a particularly squiggly solution that I found pleasing enough to post - hence ...
7
votes
1answer
147 views

A Mosaic Sudoku - SS#5

An entry in Fortnightly Topic Challenge #47: "Wacky Sudokus" Other puzzles in this series Welcome to the fifth puzzle in this series! For more information about the series, see the first ...
15
votes
1answer
894 views

Stop BorgBot before it's too late!

There was a deafening metallic thunk as the rogue AI locked the door of the PuzzlingCorp server room, trapping the engineers inside. A countdown appeared on the computer screen... and began counting ...
9
votes
1answer
431 views

Consecutive integers with digit sum divisible by 19

What is the smallest positive integer N, such that the digit sum of N and N+1 are both divisible by 19?
3
votes
1answer
106 views

Sudoku + Nurikabe = Sudokabe

The following Sudoku has a nice little twist: after solving, use the numbers in the green squares as a basis for a Nurikabe puzzle. You can create a new grid for the Nurikabe (a 9x9 grid with the ...
14
votes
1answer
201 views

This is an Odd Sudoku - SS#4

An entry in Fortnightly Topic Challenge #47: "Wacky Sudokus" Other puzzles in this series Welcome to the fourth puzzle in this series! For more information about the series, see the first ...
11
votes
1answer
163 views

Greener Grasses: Nusi's Birthday

Here is another Greener Grasses puzzle. Also, happy happy birthday to my fellow Indonesian puzzler, Nusi! I'm sorry that I realize the puzzle was broken in the last-minute checking so a single letter ...
-2
votes
2answers
157 views

How many children wear a yellow t-shirt?

The puzzle is as follows: In a certain kindergarten there are 23 children. Some of them wear a green t-shirt, others a yellow t-shirt and others blue t-shirt. A tv reporter who was on the site doing ...
8
votes
1answer
140 views

Shattered Webs - SS#3

An entry in Fortnightly Topic Challenge #47: "Wacky Sudokus" Other puzzles in this series Welcome to the third puzzle in this series! For more information about the series, see the first ...
10
votes
2answers
370 views

1, 2, 3… Trinary!!! (SS#2)

An entry in Fortnightly Topic Challenge #47: "Wacky Sudokus" Other puzzles in this series Welcome to the second puzzle in this suduko series! For more information about the series, see the ...
19
votes
1answer
366 views
+250

Stupendous Sponge

General Notes This puzzle takes the form a 9×9×9 level-one Menger sponge whose surface is divided into 648 1×1 cells. The aim is to draw a single non-crossing loop along its surface by connecting the ...
3
votes
6answers
954 views

How many children have two colored flags?

The puzzle is as follows: A classroom in kindergarten has 35 children. Each of them carry a flag of one, two or three colors. The number of only two-colored flags is double that of the monochrome ...
14
votes
1answer
553 views

The Blind Killer - a new series! SS#1

An entry in Fortnightly Topic Challenge #47: "Wacky Sudokus" Other puzzles in this series Welcome to a new sudoku series! This series will run for the duration of the current Fortnightly ...
9
votes
1answer
177 views

Familiar Five (r&r ignored)

What is the correct option/answer to this puzzle?
0
votes
1answer
132 views

How do you find the average score in an archery competition?

The problem is as follows: In an archery contest the television host says the following: The scores in this round of competition are from 0 to 20. Charles has 2 points less than Marina. Lewis has 2 ...
-1
votes
2answers
154 views

How old is Brenda?

Five friends (Adele, Brenda, Carol, Dana and Emily) were born peculiarly in consecutive years. It is known from their diaries that: Carol was born 2 years before Dana and is not the oldest of them all....
1
vote
0answers
76 views

100 boxes, only 50 attempts [duplicate]

There are 100 boxes in the room. In every box there is a note with some number from 1 to 100 (no repetitions).Person A comes into the room and checks all the boxes and notes inside them. He can (doesn'...
20
votes
1answer
529 views

2021 Unpainted Masyu

Paint some white circles to black such that the Masyu will be uniquely solvable and: Exactly 2 of 11 white circles on the left forming '2' should be painted black. Exactly 0 of 12 white circles on ...
-6
votes
1answer
76 views

Landings and stairs [closed]

Let's have two views of landings and stairs. We obtain the second VIEW B, by rotating the VIEW A 180 degrees clockwise. The distance between two landings is 8 feet, shown by the arrows. The stairs are ...
-8
votes
1answer
131 views

Shikakui Hebi: Similarities

Introduction puzzle: here So, my first Shikakui Hebi puzzle didn't go well, so I'm trying again! Only this time, no more arrows. Instead, it's now a nonogram-like! This is a Shikakui Hebi puzzle. ...
8
votes
1answer
145 views

Sashi Park: an introduction

This is a Sashigane-Statue Park hybrid. The rules might look complicated, but they're just the two rulesets smushed together. Familiarity with both genres will help. Rules Statue Park (adapted from ...
0
votes
1answer
106 views

Books on a bookshelf

On a shelf the blue book is to the right of the red book, the yellow book is in one end, the black book is just before the white and the green is between blue and white. What is the order of the green ...
-1
votes
1answer
170 views

Password with capital letters

John created a password for a social network, thinking he could forget it, he left the information below in his agenda: None of the syllables is in the word JUCOMAGO: Two syllables are in the word ...
5
votes
2answers
497 views

Nine neighbors in a hotel

Alessandra, Marta, Cristiane, Camila, Eduardo, Janice, Giulia, Mateus and Lucas are neighbors who live in a hotel. On each floor there are three bedrooms: one on the left, one in the center and one ...
9
votes
1answer
146 views

Tetrikabe: Parallelogram

Rules: (Nurikabe section shamelessly stolen from an earlier puzzle by @jafe) Numbered cells are unshaded. Unshaded cells are divided into regions, all of which contain exactly one number. The number ...
0
votes
0answers
59 views

Hundred prisoners [duplicate]

I got a puzzle that I can't figure out. A hundred prisoners are waiting to be executed. The warden comes to them with an offer. He will give each one of them a secret number, from 1 to 100, not all ...

1
2 3 4 5
51