# Questions tagged [logical-deduction]

A puzzle that needs formal logical deduction to arrive at a solution.

1,744 questions
274 views

### Replace ? by number

This chain of numbers is making confused.Help to find the answer with explanation.
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### Relationship between figures

During preparation of a test I am facing problem in solving this non-verbal question. What may the possible solution figure from A,B,C,D?
232 views

### Three Triangles by moving two match sticks

Trying two make three triangles by moving only two sticks.
181 views

### Out of six numbers in some order, we know third and fourth ranked numbers in every five out of the six numbers. Find the first [closed]

Out of six numbers 1,2,3,4,5 and 6 in some order, we know third and fourth ranked numbers in every five out of the six numbers. Find the first ranked in the order given. for example, if the ranks ...
139 views

### Finding both fake coins in a set of $5$

There are $5$ rupees on Arnav's table. He knows that exactly $2$ of the rupees are counterfeit. One of these $2$ coins is lighter than a normal (non-counterfeit) rupee, and one of these $2$ coins is ...
187 views

### Applied logic challenge problem

You must determine what can be concluded from the 60 true statements below. The numbers in each statement represent binary values (true / ...
268 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 ...
269 views

### Monty's Labyrinth

(A fun combination of two classic puzzles, hope seasoned puzzlers enjoy.) Having escaped through almost all of a labyrinth, you are met by three magical doors. Two of them lead to certain and ...
174 views

### The bottle(s) of pills of a different weight

I am a laboratory man dealing with random medicine. Day 1 I have 10 bottles of pills. 9 of them contain good pills that weigh 1.000g each, and the other one contains bad pills that weigh 0.999g each....
189 views

### Minimal tests for six ethernet lines

I have been wiring my house with ethernet cables, and was testing the connections with a simple ethernet tester: you plug two cable ends into the tester, and it tells you if the cable ends are ...
141 views

### Coloring the Chess Board v2

This is a follow up question to Coloring the Chess Board We have 8x8 Chess board like grid (8x8 2D matrix) and we are trying to color every single square/cell. But the rules are interesting; ...
198 views

### Brain Testing Logical Reasoning Puzzle

Can you answer this logical puzzle? Puzzle Source: https://www.funwithpuzzles.com/2018/12/brain-testing-logical-reasoning-puzzle.html
163 views

### Help me save Christmas - clock and word puzzle

My friend created this puzzle, it tells the Grinch's plan to ruin Christmas. I need to derive the plan from the clocks I have counted that there are 60 words. The clue is that time doesn't go ...
814 views

### What's in the mind of the SO poster?

I love the bridge I'm gonna make! This is a SO post. There are not any technicalities involved, you can ignore the code of the declare table insert ..... stuff, and just focus on the dates the OP has,...
1k views

### Coloring the Chess Board

We have 8x8 Chess board like grid (8x8 2D matrix) and we are trying to color every single square/cell. But the rules are interesting; You may start from any square you want and color that square for ...
134 views

### What was in the dead person's bag? [duplicate]

There are two people—they went to the city, and one of them died. The dead person's bag is closed and the living person's bag is open. What was in the dead person's bag?
2k views

### Blind Person Ball Game

You are blind and your friend presents you with 6 equal balls of which 3 are red and 3 are green. You friend challenges you to game to find a green ball. You must select 3 of the balls and your friend ...
64 views

### What are some good resources to practice logical puzzle-solving? [closed]

I currently own this book called "Algorithmic Puzzles" by Anany and Maria Levitin, and I am having a hard time getting through the higher level problems. I have always been interested in logical ...
2k views

### How can the younger one reach Bar Mitzvah age first? [closed]

A Bar Mitzvah is a ceremony which takes place on the 13th year of a Jewish male’s life (to the day). How could it exist that [of two Jewish boys] Jim would be born on the first day of the month and ...
90 views

### Mensa IQ test question answer? [duplicate]

What is the missing piece and why? I think it is pretty interesting but I cannot find any pattern. Do you have any idea?
88 views

### Mensa IQ-test question [duplicate]

What is the missing piece and why? I have tried to solve this but cannot figure out the rule. Can anyone find a pattern?
78 views

### Policy Maturity

Atul has 6 policy accounts which are going to mature in between the years 1997 to 2002 (both the years included). Two policies have their maturity in the same month whereas two policies have their ...
73 views

### Using only a 5-gallon bucket and a 3-gallon bucket put exactly four gallons of water in the 5-gallon bucket [duplicate]

Assuming you have an infinite supply of water. No measurement markings on the buckets. How do you fill the buckets in the right way?
155 views

### The Do-It-Yourself Puzzle

Can you solve this puzzle? You may (or may not) have noticed that this puzzle doesn't seem to have any pieces. How can it be solved without pieces? The short answer it can't. That's why for this ...
122 views

### Garden Variety Family

Some siblings* were discussing the unique mathematical qualities of their respective ages the other day, and they determined that at one point in history, the following equations were true. \$\hskip ...
2k views

### FBI number riddle

A friend sent me this riddle and I can't figure out a solution: January = 251017 February = 25628 March = 81335 April = 12145 May = 251353 June = 51064 July = 251074 August = 20186 ...
104 views

### A tale of willows and oaks

I have a big field of mine which it’s divided from that of my neighbor by a straight line of willows and oaks. Trees of the same kind are divided by 10 and 15 other trees; this means that, for example,...
425 views

### There are how many?

This is an entry in the Fortnightly Topic Challenge #41: Short and Sweet. Here is a fun nonogram I made to celebrate! Celebrate what you ask? That is for you to find out. Solve the nonogram to find ...
135 views

### Puzzle on arrangement of blocks

"The post has been edited. I am adding the answer in a few moment(references to which you are going to find in the doubts section)" Doubt: I have found out the 'initial' arrangement as given ...
196 views

### Have you been here?

I am every man. I am named after a festival. I live in the largest of spaces. I belong to the thin. Uniquely, I began twice. What am I?
942 views

### A Puzzle for a Country

Caesar's face, in his tongue. The lines on the circle line. The opposite of everything that surrounds us. The answer is the seven-letter name of a country.
190 views

### Puzzles like Sokoban?

I am looking for some puzzles like Sokoban or 15-puzzle but more difficult to solve and satisfy the following requirements: The number of possible moves at each step should be limited, let's say < ...
152 views

### A Christmas Tennis Tournament

Three friends, Charles, Hugh, and Freddy, played a one-month tennis tournament, just one match between two of them every single day during last December. During the tournament, whoever lost the day's ...
345 views

### A Problem Of Royal Proportions

One day, while enjoying a trip in one of his kingdom's cities, the amnesiac king of Country X forgets the identity of his sole son and heir. Three men from the empire rush to send letters to the king--...
399 views

### The Three Mystery People- An Actual Mystery

I believe almost everyone has heard this riddle before. There are three people in front of you. One always tells the truth, one always lies, and one answers randomly between truth and lies. You ...
76 views

### who started and when?

In a service station, five tasks – Body Wash, Brake Checking, Engine Tuning, Interior Wash and Wheel Alignment – had to be performed on a vehicle on a particular day. The order in which the five tasks ...
572 views

### Imma Reflectin Mah Lazer!

An entry into Fortnightly Topic Challenge #41: Short and Sweet The classic evil supervillain has built a superlaser. He has you tied up while he is monologuing about his evil plans. However, you ...
75 views

### Brain Buster ( Comparison of ranking)

Ali, Saad, and Hassan are all wise. Akram, Ali, and Hamza are all industrious. Akram, Hassan, and Hamza are all honest. Ali, Saad, and Hamza are all sportsmen. Which of them are not wise, but is a ...
321 views

### Assets Split Puzzle

An old woman had the following assets: ...
591 views

### age twin puzzle

Mr. Cole , his sister, his son, and his daughter are chess players. I. The best player's twin and the worst player are of the opposite sex. II. The best player and the worst player are of the same ...
261 views

### Word Cipher with seemingly random numbers

I came across this interesting puzzle and have failed to crack it for more than three days. Can you solve it? m.imdb.com/title/tt2039338/ L=9, 20, [2x5], 6, 17, 13 W=38 The only tips I ...
705 views

### PALINDROME becomes a pandigital number

Each of the letters of the word PALINDROME is assigned a different integer value between 0 and 9, for a total value for the word of 45. With the same value for each of the letters, the values of the ...
123 views

### Find the empty part

I tried several hours to figure out and tried all possible way i could think but didn't worked well. hope this question does not seem silly.
125 views

### Who stole whose hat and coat?

After a Halloween party with four guests: All guests took a coat and a hat of another guest (i.e., every one took a coat and a hat but not their own). No guest took a coat and a hat from the same ...
176 views

### 2 Concentric Circles

Total 12 individuals—A, B, C, D, E, F, G, H, I, J, K and L—are sitting in concentric circular arrangement such that six of them form the inner circle and the remaining six form the outer circle. Those ...
227 views

### Find the missing piece (edit)

I guess that these questions may use different logic independently or not i don't know. I just found one logic that fits only to the first one. *These questions are from the one of high IQ Society ...
184 views

### Find the missing box

Can't find any logic here. Can you? *This question is from the one of high IQ Society founded by Xavier Jouve Ph.D for the top 0.3% of people along the IQ spectrum.
216 views

### Horror Episode #6: Lord of the Fries

An amusement park chef named Maxwell was heading into the kitchen to clean up and shut down after another successful dinner service. He has a bit of grievance over his head as so do the other chefs, ...