# 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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### Not enough pylons!

Bob is a temp working with a construction company in repairing roads and barriers. One day Bob got called up to repair a barrier along a strip of highway. Bob will need 100 "Company X" pylons to ...
9k views

### Fit ten horses in nine boxes [closed]

Here is my puzzle: How can you fit ten horses in nine boxes? Here are the boxes: Rules: All boxes must be filled No additional boxes can be created Good luck :)
7k views

### Which is worth more - a chest of nickels or half a chest of dimes?

I have two large identical chests of exactly the same shape, volume, etc. One is completely full of nickels (each worth 5 cents), and the other is exactly half full of dimes (each worth 10 cents). ...
509 views

### What does this mean?

What is the magic word? 011021042021011012012032012032014 Clues (Read, in order, one and re-think the problem): Five letter word 'A' equals 011051 Binary (Eight digit per) Compressed ...
5k views

### Can you make 2 squares and 4 rightangled triangles using only 8 straight lines? [closed]

Can you make exactly 2 squares and exactly 4 right-angled triangles using "only 8" that is exactly 8 straight lines? I am looking for 3 different answers.
3k views

### Connect the Pipes

Each pipe shown on the left (A through I) connects to exactly one pipe on the right. To hide the answer, I have put a curtain over the pipe crossings and grayed out the pipe colors on the right side. ...
3k views

### Upside-down numbers differing by 78633

When I acquired my Mercedes-Benz car in Germany, the first thing I had to do was to get a license plate. The plate I got had a peculiar number on it. It consisted of 5 different numbers and by mistake ...
307 views

### Which one is the road (or path) to Beijing? [duplicate]

If I remember correctly, this is a question for admission to a college in China long time ago: 1) You are traveling and have reached a point on the road where it diverges to Path A and Path B. One ...
549 views

### Do I feel lucky? Well, do ya, punk?

Two Pepperbox Pistols, a Lemat 1861 revolver, a Winchester Model 1873, a Colt Thuer Derringe, two Colt 1860 Army, a Smith&Weston Model 1 1/2, a Coach Gun, and a Double Barreled Shotgun. 10 dead ...
3k views

### The broken window

A window was broken in my house and I need to find out who did it, can you guys help me? When asked who did it my friends replied with the following in order starting with 1: "I didn't do it" "1 is ...
818 views

### Kill the jokers! - Part 2

The famous and ruthless explorer Wyoming Wilbert reports in the third part of his memoires that he once visited an island inhabited by jokers and truth tellers. Truth tellers always tell the truth, ...
3k views

### 121 coins and a balance

Inspired by this puzzle... You have $121$ apparently identical gold coins. At most one of these is fake, and weighs a different amount than a genuine coin. In front of you is balance with two pans. ...
18k views

### Measuring the amount of liquid in a container without a measuring tool [closed]

The Problem Let's say you are asked to measure the amount of liquid in a container, but you are not allowed to use any direct measuring tool (such as a balance, ruler, or anything of the sort). You ...
2k views

### Determining the pattern of a 3x3 grid of hidden black and white tiles by revealing only two

I was playing a game called Space Rangers earlier, and stumbled upon a "text-adventure" mission in it, which required me to find what's supposed to be the only possible solution to this puzzle. I ...
1k views

### Diabolical dice!

I have two 6-sided dice which between them have 12 different numbers, but some of the numbers are hard to tell apart because one is the same as the other upside down (like $89$ and $68$). I throw the ...
1k views

### The 5 card problem with 2 prisoners [duplicate]

Note: I found this puzzle on quora. I don't have a solution for it. I couldn't find it referenced using google search. This time the jailor gives two of his favourite prisoners a chance to escape. ...
460 views

### Magic cutting squares with given sum

You meet a guy on the road. The following conversation follows: He: Let's play a game. Give me any natural number from $3$ to $10$. I'll call this number the grid size You: Okay, $4$. (...
129k views

### Brooklyn Nine-Nine Riddle: Weighing Islanders [duplicate]

A brain teaser posed by the character Captain Ray Holt of 'Brooklyn Nine-Nine' played by Andre Braugher during episode 18 of season 2: "There are twelve(12) men on an island, eleven(11) weigh ...
1k views

### What color is the statue? [duplicate]

This question has been tagged as duplicate of Two doors with two guards. What makes this questions different: Let me state the obvious about this question: you meet one islander. you ask one ...
671 views

### What is the next number in this puzzle [duplicate]

What is the relationship of this sequence and what is the answer for the last? 0001112359 = 4 1887145865 = 7 5528695874 = 6 0000085021 = 8 3247514251 = 0 5847962150 = ?
1k views

### Coin division puzzle [duplicate]

You are blind and sitting at a table with 100 coins on it. You know exactly 50 coins are showing heads and the rest tails, and you can tell by feel where the coins are, but you are unable to see or ...
731 views

### Jack Sparrow and The quest for the missing Compass . Part 1

Hopefully this puzzle is not as easy as the last one. Jack Sparrow wakes up startled just when he was deep in slumber, after his night out with the "Ladies". He checks his pocket and finds it empty. ...
1k views

998 views

### The devils number

You are in a room tied to a chair. The devil tells you that he is gonna ask two groups of 1000 "people" a question and then he will ask you something. If you answer correctly you go to heaven, else ...
2k views

### Camels crossing a bridge

Two merchants have 5 camels each. One fine day, one of the merchants sold all of his goods in the market and heads back to the village. He has to cross a bridge to reach his destination, and the ...
1k views

### Alphabet Number Matching

If : 888888 = T 777777 = O 555555 = Y 444444 = R then : 666666 = ? Basically you need to tell the logic along with ...
375 views

### The salary of three of Alice's coworkers

Alice would like to determine the relative salaries of three coworkers using two facts. First, she knows that if Pauline is not the highest paid of the three, then Paul is. Second, she knows that if ...