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).

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10
votes
1answer
114 views

Flying pigs arrive

You’ve built pens for flying pigs. Being, well, flying pigs, they pick their own accommodation in full accordance to their preferences. Can you figure out what creature joined them? Pigs only occupy ...
9
votes
3answers
306 views

Quick Kurodoko Puzzle: Threes and Triples

Kurodoko (taken from Nikoli) Colour cells black according to the following rules. The numbers on the board show the number of white cells from the number to the nearest black cell or to the ...
9
votes
1answer
631 views

Twelve Minesweeper mines that make twelve 4s

Can you place twelve mines on a Minesweeper grid such that they create twelve 4s? The size of the grid can be arbitrary. The mines may create numbers other than 4s, but those are irrelevant. Good ...
1
vote
1answer
53 views

What number should be in the place of “?”

I'm trying to solve this puzzle. Numbers are at triangle, and I have to solve ?-mark: 5 6 1 7 2 5 ? 7 5 Based on solutions it ...
3
votes
2answers
238 views

Thirsty men problem [on hold]

Currently, I am modeling a problem that I am working on (in distributed systems) as a riddle and I'd like to know your opinions, suggestions and solutions. You can find it here on github. Thirsty men ...
0
votes
1answer
80 views

7 prisoners, 7 hats [duplicate]

There are many red, orange, yellow, green, blue, indigo and violet hats in the prison. 1 day, 7 pirates were caught and was brought to the prison. They warden said,"I will put a hat on your head ...
1
vote
0answers
94 views

Find the probability [on hold]

There are n number of people in a room. If any two people doesn’t know each other, they shake hand. At the end, ever body announces their number of hand shake. Total number of handshake is : N(N-1)/2 ...
5
votes
1answer
118 views

*Playtest feedback request* Puzzle 2

This is the second puzzle in the series I'm working on. It's very different from the first as I tried to do different kinds of puzzles for each of these. In this one, players would have to find each ...
3
votes
2answers
514 views

Boat children and army crossing the river puzzle

During the war, a small detachment found itself confronted by a deep and wide river. However, they found a small boat in which two-children were rowing about. It was a very small boat and can only ...
15
votes
1answer
391 views

Awesomism and its awesome gods

Recently, I dived into a nice religion of Awesomism. It is pantheic, with a lot of difficult relations between gods. Twelve gods of Awesomism are split between four pantheons: Gods of cunning: Liar, ...
2
votes
2answers
150 views

Vacation duration puzzle

I was faced with the problem, that I don't think has a solution. Whether someone can confirm my guesses or prove otherwise. Following problem : Joe and Tony take a vacation at Summer camp. During ...
5
votes
2answers
170 views

Quick Shikaku Puzzle: Stars and Stripes

Shikaku (taken from Nikoli) Divide the grid into rectangles with the numbers in the cells. Each rectangle is to contain exactly one number and it's showing the number of cells in the ...
4
votes
1answer
130 views

Lucy likes Mystery

Lucy likes Jaipur but not Kerala Lucy likes Corbett National Park but not Periyar National Park Lucy likes Assam but not Telangana What does Lucy like, and why? What doesn't she like and ...
6
votes
1answer
115 views

Quick Nurikabe Puzzle: $4$s

Nurikabe (taken from Nikoli) Fill in the cells with black under the following rules. You cannot fill in cells containing numbers. A number tells the number of continuous (adjacently) white ...
0
votes
1answer
127 views

Which number is the odd-one-out in the above set?

In this number set there is something common between the numbers that makes them up into a pattern. Which one of these numbers break up the hidden pattern?
7
votes
3answers
210 views

Quick Ripple Effect Puzzle: $70$ Empty Cells

Ripple Effect (taken from Nikoli) The areas divided by bold lines are called "rooms". Fill in all empty cells with numbers under the following rules. Each room contains consecutive numbers ...
4
votes
1answer
441 views

Heyawake - why is this wrong solution

Dear people, Why does this particular android game not accept the solution on the right side? Rules in the app:
9
votes
3answers
1k views

How many days for hunting?

There are $10$ hunters who are planning to go hunting in as a few days as possible. Every single day, they choose a group of people or a person to go for hunting, the rest is resting in the camp area. ...
5
votes
1answer
186 views

Which is the missing number?

I am working on this puzzle since last week. 01 ?? 05 12 10 13 15 09 14 02 08 03 04 07 11 06 which is the missing number ?? note : answer is not 16
9
votes
12answers
3k views

Time to call the bluff [closed]

You are located outside of two rooms which have a door between them. Each room has one or more computers whose total power is unknown, so they cannot be reliably used as proof-of-work to compare times,...
4
votes
1answer
129 views

Quick Moon-or-Sun Puzzles: 2x1-Dominoes and 1x1-Checkerboards

Moon-or-Sun (adapted from Nikoli) Draw a line to make a single loop. Lines pass through the centers of cells, horizontally, vertically, or turning. The loop never crosses itself, branches ...
7
votes
2answers
267 views

Quick Slitherlink Puzzles: KPK and 123

Slitherlink (taken from Nikoli) Connect adjacent dots with vertical or horizontal lines to make a single loop. The numbers indicate how many lines surround it, while empty cells may be ...
9
votes
2answers
299 views

Quick Tilepaint Puzzles: Corridors and Corners

Tilepaint (adapted from Nikoli) The areas enclosed by bold lines are called "Tiles" and color the tiles with the following rules. The cells of a tile must all be colored with black or left ...
20
votes
1answer
920 views

Isometric Heyacrazy - Now In 3D!

This is a Heyacrazy puzzle on an isometric grid. Rules of Heyacrazy: Shade some cells of the grid. Shaded cells cannot be orthogonally adjacent; unshaded cells must be orthogonally connected. ...
7
votes
1answer
179 views

A Game of Sprouts

I have a partially played game of sprouts that I need help solving. The rules are simple (Kevin over at VSauce2 did a great job explaining it if you don't like reading, though the Yoda voice is a bit ...
-2
votes
0answers
54 views

Find 1 fake coin out of 10 coins (1 fake + 9 Original) in minimum comparisons [duplicate]

I have 10 coins where 9 are Original and 1 is Fake, which means the Fake one coin is either Heavier or lighter then Original coin. so in how many minimum comparison we need to find fake coin. links ...
6
votes
1answer
182 views

Lady C gives 11 different numbers one of which is her age to logicians A and B. What is the age of lady C?

Logicians A and B ask lady C her age. Lady C gives 11 different numbers one of which is her age to logicians A and B: 35, 36, 38, 42, 45, 46, 51, 55, 57, 61, 62 Then lady C tells the digit in tens to ...
5
votes
1answer
129 views

Heyacrazier: Big Three

This is a Heyacrazier puzzle, a variant of Heyacrazy. Rules of Heyacrazy: Shade some cells of the grid. Shaded cells cannot be orthogonally adjacent; unshaded cells must be orthogonally ...
8
votes
16answers
3k views

Ask one verbal question to figure out who is blind and who is mute among three persons

This is another "You can ask only one question" puzzle. This is an edited very restricted version There may be multiple answers but I could come up with only one. There are three persons in three ...
6
votes
2answers
289 views

Toroidal Heyacrazy: Rainstorm

This is a Toroidal Heyacrazy puzzle. Rules of Heyacrazy: Shade some cells of the grid. Shaded cells cannot be orthogonally adjacent; unshaded cells must be orthogonally connected. When the ...
3
votes
1answer
225 views

A balloon and a vacuum

You have a metal water bottle entirely filled with a vacuum and you have a rubber party balloon (lets make it red). How can you use only the bottle to inflate the balloon with the air surrounding you. ...
8
votes
2answers
2k views

Stuck on a puzzle

I have been working on a Knapp Daneben Tapa, where each clue is wrong by exactly one unit. I have tried it a few times and keep running into the same problem. I think I am solving it deductively/not ...
7
votes
1answer
154 views

Heyacrazy: Dissection

This is a Heyacrazy puzzle. Rules of Heyacrazy: Shade some cells of the grid. Shaded cells cannot be orthogonally adjacent; unshaded cells must be orthogonally connected. When the puzzle is ...
10
votes
1answer
262 views

Is this robot-programming puzzle solvable?

I have gotten into solving this kind of puzzle recently. I've found this one and after an hour of trying, I don't seem to be able to find a solution. I'm starting to think there might be an error and ...
29
votes
4answers
6k views

Half filled water bottle

If you are given a marker and a transparent water bottle partially filled with water, can you tell if the bottle is half filled or not?
6
votes
1answer
388 views

Heyacrazy: Empty Space

This is a Heyacrazy puzzle. Rules of Heyacrazy: Shade some cells of the grid. Shaded cells cannot be orthogonally adjacent; unshaded cells must be orthogonally connected. When the puzzle is ...
1
vote
1answer
145 views

Don't Fail MY Exam [duplicate]

A professor decides the following grading scheme in his class. After the final exam is graded, he keeps all the papers upside down on his table in a random order so that no student can recognise his ...
0
votes
0answers
83 views

Tales of Two Cities (With no Gas Stations in between) [duplicate]

Two cities A and B are 100 miles apart. A person has to travel from one city to the other in his old old car, which can travel only 50 miles with its tank full. Unfortunately, there are no gas ...
7
votes
2answers
218 views

Heyacrazy: No Diagonals

This is a Heyacrazy puzzle. Rules of Heyacrazy: Shade some cells of the grid. Shaded cells cannot be orthogonally adjacent; unshaded cells must be orthogonally connected. When the puzzle is ...
10
votes
2answers
193 views

Heyacrazy: Careening

This is a Heyacrazy puzzle, designed at request of testsolvers of previous puzzles who wanted to see how longer diagonals would work. Rules of Heyacrazy: Shade some cells of the grid. Shaded ...
12
votes
2answers
587 views

Slitherlink Fillomino hybrid

This puzzle is a combination between a Slitherlink and a Fillomino. You should put a number in each square and draw a single closed loop over the grid such that the following properties are satisfied:...
9
votes
2answers
957 views

Earth rotation discrepancy

Some time ago, I discovered that planet earth's sidereal rotation period equals 23 hours, 56 minutes, and 4.1 seconds (see for example this Wikipedia article). The sidereal rotation is the rotation of ...
9
votes
2answers
168 views

Heyacrazy: “LMI”

This is a Heyacrazy puzzle, originally constructed for a test for Logic Masters India. Rules of Heyacrazy: Shade some cells of the grid. Shaded cells cannot be orthogonally adjacent; unshaded ...
8
votes
1answer
156 views

Heyacrazy: Forks

This is a Heyacrazy puzzle. Rules of Heyacrazy: Shade some cells of the grid. Shaded cells cannot be orthogonally adjacent; unshaded cells must be orthogonally connected. When the puzzle is ...
13
votes
1answer
650 views

Heyacrazy: Crosses

This is a Heyacrazy puzzle. Heyacrazy is an original genre, inspired by the "two border" rule of Heyawake and Heyawacky. Rules of Heyacrazy: Shade some cells of the grid. Shaded cells cannot ...
15
votes
2answers
445 views

Heyawacky: Ace of Cups

This is a Heyawacky puzzle. The rules are the same as Heyawake, but non-rectangular regions are allowed. Rules of Heyawake: Shade some cells of the grid. Shaded cells cannot be orthogonally ...
6
votes
1answer
940 views

Dodgy Dies: The Puzzling Premiere

Inspired by the "Treasure Hunter Monolith" minigame from Danganronpa V3 Dodgy Dies Guide Terminology Block - a single die on the grid. Cycle - a list of blocks Value - the ...
19
votes
2answers
1k views

Heyawake: An Introductory Puzzle

This is a Heyawake ("divided rooms") puzzle. Rules of Heyawake: Shade some cells of the grid. Shaded cells cannot be orthogonally adjacent; unshaded cells must be orthogonally connected. ...
3
votes
1answer
188 views

Missing Number in a Seven Segment Circle

What number should replace the question mark? Please be helpful. If you have the answer, please reply to this post with the explanation and answer. If you don't have the answer, then don't comment. ...
-4
votes
1answer
151 views

A riddle from Candy Cadet [closed]

I am Candy Cadet, come get your candy here. I have candy all day, everyday. Candy. Candy. Candy. Now I will tell you a story about a young woman who was sealed in a small room. In the room was a ...