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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Friend gave me 3 logic numeric puzzle and i dont know how to solve it

Question 1 5:1121681/25201, 3:?/51893 Question 2 15/20, 32/51, 78/5780, 34/? Question 3 1/9, 10/24, 1000/?
1
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1answer
35 views

Mathmatical equation answer [closed]

I think there must be a way to solve this but I can't get there Green + Blue = Yellow Red + Green = Purple Yellow - Purple = Red Red + Green + Blue = 9 I have made some progress And but I run ...
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1answer
61 views

The Hardest Logic Puzzle Ever! I guess [closed]

If a giraffe has two eyes, a monkey has two eyes, and an elephant has two eyes, how many eyes do we have?
11
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8answers
4k views

Three people wearing hats

Ms. Doha gave hats with different non-zero single digits (two of which are factors of the third) to Ms. Haha, Ms. Lola and Mr. Hehe. The three of them can't see the digits on their own hat though they ...
3
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1answer
87 views

Perambulating ants 2

The ants from this puzzle have been placed into a new arena: a cross-shaped hallway with a pillar (black square) in the centre and four statues (numbered 1-4) set symmetrically. The ants, like last ...
7
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3answers
783 views

Super Secret Cookbook

You requested the password for a super secret cookbook and received an SMS with the following content: 77733666688833 2555555 777772222337777 2663 777337555222233 84433 6688622337777777 9444844 ...
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1answer
119 views

8-puzzle in 12 steps

This quiz is about the 8-puzzle. It is a board with 9 spaces. There are 8 tiles with the numbers 1 through 8. One space is empty (.). You slide the tiles around the ...
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0answers
104 views

What will you do for this country? [closed]

Suppose 70% of people in a country of 100 crore population loses their jobs. What will you do to provide a steady income($10/day as per current value)those people who lost their jobs?
11
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2answers
756 views

Perambulating ants

An ant is a methodical creature, and the ants in this puzzle are particularly so. When they start walking they always walk in a straight line, and when they reach a boundary they always turn exactly $...
8
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2answers
278 views

Another coin weighing puzzle. But this is simple!

There are many coin weighing puzzles. So a general attribution to all of them. (And I will fully understand if you completely ignore this one). Hope this is not a duplicate. But I think this is a ...
13
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2answers
751 views

Hearts and Spades in a Row

From a deck of playing cards remove hearts ace to seven, and spades ace to seven. Now place them on a table in a row so that the number of cards between the two aces is 1, the number of cards ...
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0answers
64 views

Mystery Sudoku = new variant [closed]

I have created a new sudoku variant: the Mystery Sudoku. One of the 9 digits is the mystery digit. Try to find its value and its locations. The numbers outside the grid are the sum of 2 (at the bprder)...
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1answer
160 views

Stuck on (a couple of) diagramless kakuros

I was working through OAPC 6 (http://oapc.wpc2009.org/archive.php?id=46). I was having trouble with the diagramless kakuros. The rules for this puzzle are as follows: Place the numbers $1-n$ (7 and 9 ...
37
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17answers
6k views

XKCD inspired logic puzzle

I came up with a logic puzzle inspired by this xkcd comic. I don't yet have an answer, and I am wondering if anyone can come up with one. You are in a room with three doors. Two of the doors lead ...
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10answers
13k views

They use me… What am I?

I'm complex inside,but easy on the outside. I'm loud for one,but quiet for others. I'm used to getting hit,but there's no alternative. I die as fast,as I rise again. What am I?
2
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3answers
175 views

Blood Type Puzzle 2: Am I Pure Blood?

This puzzle is similar to the first puzzle but with a few twists: In this question: both my mom and I are blood type B. But this time I don't know my dad's blood type. My mom said her parents ...
3
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8answers
444 views

Two doors, two guards, and two keys

Table of contents Introduction - read about where the puzzle comes from. The puzzle - read the puzzle itself. Warming up - read about solutions to a simpler variation of the puzzle. Introduction (...
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2answers
2k views

Mensa Norway last 3 questions

I had no problems with solving first 32 questions from http://test.mensa.no but the last 3 questions are totally bugging me out even knowing the answers. Could anyone help me getting the logic behind ...
10
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0answers
543 views

An enrypted clue for the police

A well known German drug dealer contacted his accomplice with an encrypted note. The police caught the accomplice during a drug deal and found a note in his backpack. Note: (For those who can't open ...
10
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9answers
11k views

Survive from death by asking the right question from trolls

You are in the intersection of two roads, there is a troll in the beginning of each road. One of them is liar (always lies), and one of them always tells the truth. One of the roads, ends to your ...
4
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1answer
212 views

Ask, and you shall receive

Request of me twenty, receive of me twenty. Request of me sixty, your behest will be fulfilled. Request of me eighty, you'll be given the same; but ask for one hundred, and you will get only sixty. ...
7
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1answer
716 views

Queens full of jacks

(Note: I doubt that this puzzle is complex enough to post it here, but I still took a try.) There are 3 queens and 2 jacks (a full-house combination from poker) taken from a deck with standard suits, ...
55
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16answers
10k views

How can I convince my colour blind friend that his two balls have different colours?

This question is inspired by this one, inspired by another Stack Exchange network question. My colour-blind friend has two balls, one red and one green. However, he is convinced that they are the ...
15
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3answers
8k views

The Harry Potter Potions Riddle

A simple riddle from the first Harry Potter book. You are in a room with seven potions. There is a doorway ahead and a doorway behind, both engulfed in flames. Which potion will allow you to move ...
2
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0answers
35 views

Using a balanced scale find the minimum and maximum weight of items [duplicate]

There are 1567 items with different weights. The goal is to find the item that has the maximum weight out of the 1567 and the item that has the minimum weight out of the 1567. For this you are allowed ...
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5answers
3k views

A simple murder mystery puzzle that I came up with

A woman was found dead in her apartment. She was hanging from the ceiling but the detectives deduced that it was not suicide because of the bruises on her body (indicating a struggle) and the mess in ...
7
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1answer
992 views

A fish story on aymara language

Interesting story I stumbled upon: Aymara is a South American language spoken by more than 2 million people in the area around Lake Titicaca. Among the speakers of Aymara are the Uros, a fishing ...
10
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5answers
449 views

2 fake coins from a pile of 30 coins

You need to find two fake coins from a pile of 30 coins. You know that a fake coin has a different weight to a real coin, but you don't know whether it is lighter or heavier. You also know that all ...
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12answers
2k views

2 Person Same Number Verification

Alice and Beth both receive a random integer from 1 through 10, inclusive. They only know the number that they are given. The two of them want to come up with an algorithm to check that their ...
7
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2answers
202 views

Turning a fan on

I bought an air purifier which has [off, low, medium, high] settings and a single button. If it is on, the first button press activates the lights and subsequent presses increment the level with off ...
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1answer
145 views

Missing Number Picture Puzzle

This is is logical reasoning puzzle in which your challenge is to find the relationship among the given numbers and then find the value of the missing number. Source: https://www.funwithpuzzles.com/...
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5answers
2k views

Three 50/50 guesses

Three friends enter a quiz-show as a team, the final round of the show is all or nothing, they only get their prize if they can win this round. Three boxes labelled 1, 2 and 3 are placed in a room, ...
8
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3answers
1k views

30 fake coins out of 99 coins v2

Follow up question to my other question, but totally different methodology required. You are given 99 coins which consists of 30 fake ones. You also have a digital balance scale with perfect ...
9
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1answer
312 views

Grid Deduction Deduction: Cave or Tapa?

The following grids can be solved using either Cave or Tapa rules. First, determine what kind of puzzle each grid represents. (They can both be of the same kind, or there could be one of each kind.) ...
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2answers
1k 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 ...
14
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9answers
3k views

Which person is telling the truth?

A person was killed. There are 4 suspects. A says C is the killer. B says C is the killer. C says that B is lying. D says that it wasn't him. There is only one person telling the truth. Who is this ...
6
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3answers
1k views

Zombie horde incoming! [duplicate]

Here is a puzzle I found on youtube's Ted-ed channel and found quite fun to solve. You and 3 more people are for some reason running away from a horde of zombies in the darkness while holding a ...
9
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1answer
435 views

Cryptic Battle: Welcome to PSE!

Inspired by jafe's Double feature series. The following is a hybrid Star Battle and diagramless cryptic crossword. Solve the clues and the grid, then place the clued words in the grid in a logical ...
117
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7answers
42k views

Mensa IQ test question made by www.bergmandata.com

Which of the 8 tiles below is missing? I've been trying to figure out the answer to this question for quite some time. Can anyone spot the pattern?
6
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2answers
644 views

Is there a way in which all the members can be seated?

Here's a puzzle where it is very difficult to find a possible seating arrangement of all the members. I have been struggling to solve it. I have devoted so much of my time trying to figure out ...
17
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1answer
497 views

Octagonal Kurotto

This is a Kurotto puzzle. Rules of Kurotto: Shade some cells to form connected groups of shaded cells. Circled cells are unshaded. If they have a number in them, that number tells you the sum ...
3
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0answers
217 views

The Weird cipher password?

During your search to the ' great hidden computer virus ' , you realized that you are just a password from accessing it. Frantically , you searched for a clue that might help you . At last you ...
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0answers
47 views

Is it necessary to state that there is a logician with a blue hat in this 100 logicians puzzle? [duplicate]

I've been discussing the logic puzzle where 100 logicians, all wearing blue hats, are trapped in a room and told: they can leave when a bell rings if they know they know they are wearing a blue hat, ...
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3answers
587 views

Carousel Seating Logic Puzzle

Puzzle from my good friend and fellow Sporcle user, AuroraIllumina! Eight children are riding the carousel: four girls (Anna, Beth, Claire, Diana), and four boys (Eric, Frank, George, Henry). It is ...
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3answers
2k views

Can you put L trominos to fill the figure?

In the above picture, there are 24 squares. Can you only use L trominos to fill the figure? If yes, give an example. Otherwise, please explain why. An L tromino is like this:
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4answers
859 views

Knights and Knaves in the Wild West

Late at night at a bar in the Wild West only two cowboys from out of town are left, playing poker with the barkeeper. One of them cheats, so another throws over the table and they have a fistfight (...
43
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11answers
8k views

3 doors, three guards, one stone

You are in a room with three doors. Behind two of them, the darkest pit of hell waits for you to make a mistake. The other door leads to heaven and freedom. Each door is guarded by a guard: Michael, ...
5
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1answer
241 views

Identify the Drink Given Other Info

There is a smooth dance, a ball sport, a country's capital, a month, and a drink. What's the drink?
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4answers
689 views

Sharing cake among 9 or fewer people

You are expecting guests to your birthday party. You know that there will be at most 8 guests, but you don't know how many will actually come. What is the smallest number of pieces you should divide ...
12
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3answers
2k views

Can you catch the thief?

This was a puzzle I recalled from university a couple of years back. I don't know what the original puzzle is but if someone knows it, please let me know so I can credit the source. You are a police ...