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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).

6
votes
1answer
186 views

Hiker’s Cabin Mystery | Pt. V

Be sure to see the previous parts and solve Part II because that’s the only one without an answer! After you’ve unlocked the mystery of the map, you go to (Solution to Part IV) to try and find this ...
0
votes
1answer
153 views

Every Answer To All Puzzles Here - Secret Found

BREAKING NEWS: The magic stone which reveals all answers on this site has been located! The only known photograph of the stone: The Stack Exchange Adventure Club has received word that the "All ...
2
votes
3answers
2k views

Should I take the antidote? [closed]

A new disease has been discovered in the world, it is called Blue. Statistically 1:1000 people in the world has it and it makes your whole skin blue in a few weeks after getting the disease but not ...
0
votes
1answer
72 views

Find the missing parking space number [duplicate]

Each space in this parking area is numbered. The parked car covers one of the numbers. What is the number? For reference, the parking numbers are $16,06,68,88,X,98$ where $X$ is the hidden number.
4
votes
2answers
192 views

The CompuTaria Quest - A young Wizard's journey

Once Upon A Time In A Land FAR, FAR Away... Our adventure begins in the enchanted land called "CompuTaria". You are, "Binaryian" a 3rd year Wizard In Training. Today began like any other day - you ...
42
votes
11answers
8k views

3 doors, three guards, one stone

You are in a room with three doors. You find out that behind two of these doors, the darkest pit of hell is waiting for you to make a mistake. The other door leads to heaven, where you obviously want ...
12
votes
12answers
5k views

Coin Game with infinite paradox

Here’s the puzzle/problem: Let’s presume we are best friends. I own the house next to you. I make a gaming proposition along the following lines: You throw a coin over and over again. So long as it ...
2
votes
2answers
106 views

Find the set of letters corresponding to a set of words

Each word in the following list corresponds to one letter: rôle résumé Jalapeño xoriço ö führer The combination of letters can be represented as ----uu Here, the -'s represent the missing letters. ...
17
votes
2answers
2k views

We are two immediate neighbors who forged our own powers to form concatenated relationship. Who are we?

Our concatenated number is $ \overline{ABAC}, $ where $ A, B, C $ are all positive digits (1 - 9). Our relationship is $$ \overline{ABAC} = A^A + B^B + A^A + C^C $$ Who are we?
6
votes
1answer
195 views

Hiker’s Cabin Mystery | Pt. IV

You’ve gotten into his computer and opened the correct file. Ready to read? The file turned out to be an image... of a map. Where is our mystery hiker hiding out and how do you know?
5
votes
1answer
134 views

Find the immediate square dancing neighbors, they dance together to perfect square

We live in a community of houses sequentially numbered from 1 to 100. We all love square dancing but only two immediate neighbors are joy to watch. If you concatenate their house numbers, it forms a ...
1
vote
3answers
464 views

Solve for the Number in the number..square..cube relationship

Each letter stands for a distinct digit...no computer or calculator needed. Just pure logic and some mental multiplication. CUBE is a concatenated number and it is a cube. X denotes multiplication. (...
9
votes
1answer
604 views

Narcissistic cube asks who are we?

I am a five digit narcissistic cube who likes to display my root right upfront. I also have hidden it in the back of my four digit cube brother. Who are we?
18
votes
8answers
2k views

30 fake coins out of 99 coins

You are given 99 coins which consists of 30 fake ones. You also have a digital balance scale with perfect precision that shows how much difference between weighs you put on. For example, if you put 10 ...
-9
votes
1answer
96 views

Number of days in a normal year expressed with five consecutive positive integers [closed]

Given $D$ is the total number of days in a normal year $a$, $b$ are positive integers $P$, $Q$, $R$, $S$, $T$ are consecutive integers Figure them out by combining the following six expressions ...
-2
votes
2answers
157 views

Complete the following verbal analogy!

MAKE : DALE :: (?) : PALE Hint: pattern recognition or semantical relation (?)=solution containing 4 letters : means 'to' , :: means 'as'
7
votes
1answer
134 views

Emoji-Mutating Machines

I have built twelve emoji-mutating machines, each of which changes one characteristic of an emoji—for example, adding glasses, removing a tear, changing a smile to a frown, and so on. Each machine has ...
62
votes
4answers
4k views

Gerrymandering Puzzle - Rig the Election

The following graphic is a map of the country Mathlandia: You are currently running for reelection, but the polls aren't exactly in your favor. Each square in this grid is a county. Counties with a ...
17
votes
4answers
1k views

Single Colour Mastermind Problem

Imagine we're playing a game of mastermind with the usual eight colours, only this version has six holes across in which to place colours. And to make it easier for you I tell you that I have filled ...
56
votes
2answers
8k views

It's getting harder and harder not to offend anyone

Andy, Bob and Chuck are old friends meeting for the first time in years. Scene 1: At the intersection ANDY: Hey guys! Long time no see! BOB: Hey, nice to see you, Andy! Have you seen Chuck? Is ...
1
vote
3answers
225 views

Can someone solve this kakuro?

Can someone solve this? Please tell me how you did it. Source: Puzzle Page app
6
votes
1answer
222 views

Dividing the gold

There is a king and 3 women in a castle. One day, the king give 3 women a total of 100 golds. He said that each woman can propose an idea to share the gold among themselves. If the proposal passed ...
3
votes
2answers
133 views

SafeCracker #1 - Look who's talking

The Plot You work for a tech company in Tampa, FL. Recently there was a break-in, and the company's trade secrets were stolen. Company PI have tracked the briefcase containing the secrets to the ...
15
votes
2answers
2k views

Virus Detected - Please execute anti-virus code

Virus Detected!!! Your computer, which is represented by the grid pictured, has been infected. The bugs are clearly marked. It's your job to inject your awesome anti-virus code in the proper computer ...
0
votes
1answer
73 views

Place Your Bets 3 , last of the series

A harder sequence to figure out... What are the next 4 cards, including suits?
1
vote
1answer
51 views

Place Your Bets 2 - In sequence, of course

Your Cards... You have to figure out what the next row of 4 cards will be. There is a pattern in there somewhere, promise. Good Luck
2
votes
1answer
83 views

Place Your Bets - in sequence, of course

Your Puzzle There is some sort of pattern in cards below. Simply figure out what the next card should be. Note: You cannot re-use a card already in play.
3
votes
2answers
86 views

A Wine Problem for Puzzlers [duplicate]

Simple Follow the instructions on the label. In case you the image is too small, Given three bottles: 8, 5 and 3 liters capacity, divide 8 liters in half (4 + 4 liters) with the minimum number of ...
-4
votes
1answer
213 views

Write an equation using constants e, i, pi and phi [closed]

Without using numbers and using only permitted math operators, write an equation using the constants $e$, $i$, $\pi$ and $\phi$. Allowed operators..exponent...multiplication..subtraction...only. Use ...
-1
votes
1answer
83 views

The Puzzle of Puzzles - Pieces of Logic

The Story Johnny has added several new jigsaw puzzles to his somewhat large, and unusual collection this year. He likes Computer related puzzles, and the outdoors, as well. Your job, Determine each ...
2
votes
0answers
113 views

The Bad Clue Puzzle

The Jumbled Story Johnny might have had a couple beers when putting this one together. What he intended was a logic puzzle of friends, their favorite classic computer system, and how they used to ...
6
votes
2answers
201 views

Top Game Developers

Top Game Developers Back Story Okay fellow puzzlers, I hope you packed your lunch, this one is my most challenging puzzle to date... Johnny is writing an article about some of the top-selling ...
4
votes
2answers
139 views

Hidden Treasure Logic Puzzle

Ok, fellow puzzlers, here is my latest puzzle. They are getting progressively harder. Back Story While snooping around your grandpa’s attic, you came across a bunch of scribbled notes. They were in ...
5
votes
1answer
123 views

Video Game Auction - Logic Puzzle

Puzzle Difficulty: Very Challenging The Story Johnny loves his classic video games. He has collected most of them. Unfortunately, though, Johnny's Grandmother needs an expensive operation. He has to ...
3
votes
2answers
145 views

Looking for a Logical Puzzle with Scalability

I hope I am in the right place to be asking a question like this! That being said, I am experimentalist in need of a 'good' logical puzzle. There are aspects of the puzzle I would like and other ...
4
votes
6answers
2k views

Find 108 by using 3,4,6

Assemble a formula using the numbers $3$, $4$ and $6$ in any order to make 108. You may use the operations; $x + y$ $x - y$ $x \times y$ $x \div y$ $x!$ $\sqrt{x}$ $\sqrt[\leftroot{-2}\uproot{2}x]{...
1
vote
2answers
168 views
18
votes
9answers
1k views

One-one communication

5 people are standing in a circle - person A needs to tell his salary to person B, but none of the others should know A's salary. How is this possible, if every person only whispers to the person on ...
-2
votes
1answer
528 views

Don't be Greedy

this is a cs50 puzzle day 2019 question as you would know the questions have a one english word answer. will someone like to collab with me to solve all of them? there are 10 more of them.
1
vote
2answers
202 views

Sequence made of symbols

(My friend in real life gave me this)That's the original sequence: ⬅↕➡,⬅↕,➡,⬅,?,?,↕➡ I'm going to use other symbols to make it readable: (/), (/,), (/, ?, ?, /) I've noticed that the comma ...
12
votes
1answer
592 views

Reflections in a Square

An ideal billiards table (no friction, ideal reflections off of the walls, no pockets) is shaped like a square. From the bottom-left corner, shoot a point-sized cue ball at some angle. What is the ...
10
votes
1answer
587 views

Girl Hackers - Logic Puzzle

StackExchange Top Ranked Girl Hackers The Stack Exchange Hacking Federation (of course fictitious) has just released its list of top-ranked female hackers for the year. Using only the clues below, ...
12
votes
5answers
2k views

Sum letters are not two different

The following letters all have something in common which may not be obvious at a first glance: A B D H P No other letters share this attribute. Hint More ...
3
votes
5answers
355 views

A story about liars

Evelyn, Skylar, Alayna, Madelyn, Jonathon, Lara, Alyin, Felix, Iris, Bob and Roslina live on an island where some people always tell the truth, and the rest always lie. Roslina says "Alyin and Evelyn ...
18
votes
2answers
57k views

A man with two red pills and two white pills

Story: A Color blind man is travelling in a somewhat famous ship that had just a few people on board. Everything was smooth sailing for some days. One day,the man heard some noises from outside when ...
10
votes
2answers
1k views

8 Prisoners wearing hats

A warden lines up these prisoners. He announces, "I see a white hat." He then leaves the room. Every few minutes he comes back in and asks if anybody knows their hat color. Anyone who figured it out ...
20
votes
12answers
118k views

Four prisoners wearing black and white hats

There are four prisoners. All four prisoners will be freed, if at least one of them correctly guesses the color of the hat on his head. They can't speak to each other, and they can't touch each other....
27
votes
12answers
2k views