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Questions tagged [logical-deduction]

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

12
votes
2answers
335 views

Cannibalistic Words

Drawing from the word pool below, find the twelve Cannibalistic Words. (Note the no-computers and logical-deduction tags.) WILD _ _ ☐ _ _ _ _ ☐ PENS ☐ _ _ _ _ ☐ _ _ DEED _ _ _ ☐ ☐ _ _ _ BLED ...
3
votes
1answer
207 views

A Battle of Dysfunctional Kings (Chess)

So recently I've learned about fairy chess and I've decided to write a puzzle based around the topic. Today's variation features a chess board which is missing eight squares (A1, A8, C3, C6, F3, F6, ...
17
votes
2answers
2k views

Fairy Chess #1- The Mastermind

(Fairy chess is a general term for any kind of chess variant with pieces that aren't used in the normal game) (Inspired by The Black Prowler (chess)) In this variant, white has their entire army ...
7
votes
2answers
930 views

Ten people sitting at a round table

Ten people are sitting around a circular table according to the following conditions: There are two persons between X and U. Y is neither adjacent to X nor opposite T. P and T are adjacent to W. Q ...
8
votes
8answers
383 views

Infinite amount of theorems

We have an infinite amount of theorems $A_1, A_2 \ldots A_n$. Each one of the theorems says: "All of the following theorems are false.". Is there a single one of these theorems that is true?
0
votes
1answer
155 views

Husbands and Wives around a Circular Table

Please anyone tell approach. Source : time.com
6
votes
1answer
206 views

Truth tellers or liars among two people

Two guys, number One and number Two. You ask number One "Is there a truth-teller among you?". He replies and you have the answer to your question. What is number One and what is number Two?
1
vote
1answer
226 views

What is the value of X?

24 6 63 132 4 14 23 x 17 The answer is either : 21, 14, 3 or 2
-6
votes
4answers
188 views

What was the police officer's idea? [closed]

Two police officers suspected a man of kidnapping. Without sufficient evidence they couldn't search his car or his home. They also couldn't interrogate him. One officer had an idea which later led to ...
9
votes
1answer
225 views

Six gems, six shelves, and far too many puzzle rhymes

An entry in Fortnightly Topic Challenge #39: Deep Down in the Dungeon 1. You enter a well-lit, round chamber. As the party enters the room, the door behind you slams shut. No amount of effort can ...
6
votes
1answer
205 views

The Temple of the Niffugcam

An entry in Fortnightly Topic Challenge #39: Deep Down in the Dungeon 1 The party has entered the legendary Temple of the Niffugcam to recover the legendary artifact, also named Niffugcam. After a ...
5
votes
3answers
957 views

Engineers logic test for a job [duplicate]

Two engineers go to a job interview. They are introduced and told they are looking for people with team working skills. Without time to talk or get to know each other, they are guided to two different ...
3
votes
2answers
255 views

Weight, Height and Age of 6 boys

Six Boys – S, R, V, A, H and K – are ranked on the basis of their weight, height and age such that the heaviest person is ranked 1 and the lightest is ranked 6, the tallest is ranked 1 and the ...
2
votes
1answer
187 views

A Number Pattern Puzzle

I can't crack this one. Any help is appreciated,
3
votes
1answer
186 views

Portrait Puzzle

In an art exhibition held during the 70th Independence Day celebrations in Delhi, five portraits of five wellknown freedom fighters namely Mahatma Gandhi, Bhagat Singh, Lal Bahadur Shastri, Lala ...
1
vote
1answer
87 views

Minesweeper challenge #3

I seem to have run into yet another "unsolvable corner" while playing Minesweeper. The following segment is taken from the bottom right corner of the puzzle. There are 5 mines remaining, and all ...
4
votes
0answers
256 views

My brain froze trying to solve this [closed]

Try to figure out the missing numbers!
14
votes
3answers
575 views

Lau's Labyrinth

An entry in Fortnightly Topic Challenge #39: Deep Down in the Dungeon 1. Our heroes open the door and the remaining doors vanish accompanied by the sounds of grinding stone. The magnificent structure ...
11
votes
5answers
559 views

Distinct ball weights but balance on the scale

You are given eight identical-looking balls and a two-sided scale. All of the ball weights are distinct, but if you put 4 specific ones on the one side, and the rest on the other side of the scale, ...
9
votes
4answers
333 views

Different Teapot Riddle - fanmade

As inspired by @gabbo1092 in the first of this kind of riddle (see this for an example of how the answer works), I thought I'd come up with another riddle. Rules: I will give you a number of clues. ...
1
vote
3answers
174 views

Staggered Race Puzzle

This is puzzle on staggered race This is the Solution is given for question in image Question : What could be the maximum time for which Neeraj could have been in the second position in the race? ...
4
votes
2answers
184 views

Minesweeper challenge #2

Again, I seem to have run into another situation where there doesn't seem to be a definitive set of squares to tap to solve a Minesweeper puzzle. What squares should I tap to maximize my chances of ...
5
votes
7answers
2k views

Hard 4x8 chocolate bar Riddle v2

This is inspired from this puzzle: You have $4$x$8$ chocolate, you can cut only straight with the knife. What is the least amount of cutting required to have $32$ pieces of 1x1 chocolates? and ...
0
votes
1answer
73 views

Circular Arrangement 4 parameters

P, Q, R, S, T, and U are six sports persons who are also recipients of Arjuna award for the year 2017. During the felicitation ceremony, the six persons were seated around a circular table. Three of ...
3
votes
2answers
161 views

Third and Triple

This is inspired from Half and Double Value. Please see that puzzle, too. Okay, so now you're really bored. A good puzzle wastes time, so you make one. Try to find the smallest number, that, when ...
2
votes
1answer
101 views

Circular Arrangement

A, B, C, D, E and F are six students seated around a circular table. Each of them is a specialist in one field from among Finance, Marketing, Operations and Strategy with at least one student in each ...
-3
votes
1answer
216 views

5 ferries, their capacities and ticket price

Five ferries - King's Way, Speedster, Sea Monster, Astar and Blue Surfer operate to Manuchan Island. The capacities of these ferries are 25, 30, 40, 50 and 60, not necessarily in the same order. Each ...
14
votes
1answer
232 views

Finding the hidden path (new grid puzzle concept?)

I was toying around with grid-based puzzles, and I can up with a format that I'm not sure exists yet, and from my testing leaves only one solution. (If it exists or is broken, please let me know so I ...
6
votes
2answers
224 views

The Story of Jason & J____

One man was fighting another person. The victim was being punched and kicked and shoved, and the attacker had no intentions of stopping. Then, two priests walked by. One of them noticed the fight and ...
0
votes
1answer
306 views

Solutions Zebra puzzle - Blood Donation [closed]

Where can I check for solutions to the Blood Donation (Zebra puzzle) from Brainzilla? I tried their website, but they did not have an 'answer section' available yet. I emailed them and they gave me ...
2
votes
2answers
265 views

Had some real trouble with this logical sequence today [duplicate]

Reasonably sure I didn't get the job, but this particular part of their test really baffled me. The numbers of angle brackets in each row and column should probably add up to ten, so the missing ...
7
votes
2answers
911 views

Don't put yourself out, dear

I asked my mother the other day, "What do you want for dinner? I'll get you anything your little heart desires." My mother, true to form, radiated the stereotypical motherly vibe: "Don't worry about ...
1
vote
1answer
303 views

Which of the six tiles is missing? — An IQ Test Question

Which of the six tiles below is missing? I honestly do not know the answer. I took a screenshot of this from an online IQ test a while back. If you know where it is from, please let me know, and I ...
7
votes
3answers
242 views

Should Dr. (Indiana) Jones do it? Another Jones Adventure

This puzzle is linked to the previous " Should Dr. (Indiana) Jones do it?" puzzle After walking thru the rain drenched tropical forest Jones finally arrived at his destination. A stone building with ...
15
votes
5answers
2k views

Bizarre Love Triangle

I work in quite an unusual office. Everybody who works here has a colour for their surname! It’s a bit like that old board game Cluedo, except nobody has been murdered. Still, there is a bit of a ...
5
votes
9answers
3k views

What is 5 equal to?

Can you find what corresponds to 5? If: $$1=5$$ $$2=6$$ $$3=7$$ $$4=8$$ then, $$5=?$$ Note: the answer is not 9.
3
votes
1answer
101 views

Just try and Understand this Riley riddle, bet You can't.

My Prefix is really good at this. My Infix goes by quite fast. My Suffix is adorable.
18
votes
6answers
2k views

Can YOU guess this Riley Riddle?

My Prefix returns us to the dark ages. My Infix belongs to someone. My Suffix has annoyed me since birth. Hint 1: Hint 2:
6
votes
2answers
320 views

$9$ coins into three groups

You are a lab assistant and your prof asked you something very specific: There are $9$ coins made of three different materials with different densities in front of you, but they look the same, divide ...
1
vote
1answer
68 views

Points in the tetrahedron

There is a regular tetrahedron with edge ledge of $2$ units. Your task is to put as many points within the volume occupied by the tetrahedron. But there is a condition: there has to be at least $1$ ...
2
votes
1answer
59 views

Random Riley Riddle Number 2

My Prefix is a place to stay, but famously said to go away. My Infix happens where you might find a trooper. When two become one, it really is super. My Suffix means to ignore, but spell it ...
2
votes
3answers
212 views

Fami-liar Situation

Exactly one of Sam or Tom has family visiting. They make these statements: Sam: "Tom has family visiting, but I don't." Tom: "Sam is lying, or I am lying, or possibly we're both lying." ...
4
votes
1answer
196 views

Making transmitting data safe - double reading

Hopefully in the spirit of the Fortnightly Challenge 3rd Sept 2018 - Reusing Information If we are given a binary string, say: 1100010101100011 and we wish to transmit it safely, we might use '...
3
votes
4answers
250 views

Classic 2 Guards But With 3 Doors Instead

So the rules are almost the same : You get to ask just one question to whichever guard you want to (just 1 guard; asking both guards is not allowed) There are 2 guards, one tells the truth and ...
3
votes
1answer
99 views

Our Big Test is Tomorrow!

My two friends and I are going stir crazy, trying to figure out what we should do today. Maybe you can help! We've narrowed it down to a few choices. We could: Visit the mouth of a river on an ...
3
votes
1answer
120 views

Anyone can do a Riley Riddle

I went through a random word generator until I found a nice one to make a Riley out of: My Prefix can crunch, wash, or rock. And can be found prominent, on those who aren't scared. My Infix ...
4
votes
3answers
171 views

Fix the perfectly ordered equation

This question is follow up to Something is wrong with the equation This time our numbers are given as below included each numbers on a keyboard order and some basic math operators next to each other ...
3
votes
1answer
150 views

Big Table in a Conference

A group of people is sitting around a round table. They have a coffee break. When they get back, they sit down randomly. Interestingly, they all notice that the 8 closest people sitting next to ...
1
vote
1answer
98 views

How to divide them into groups

You have found $13$ gold coins and strangely their weights are from $1$ to $13$ grams (such as $1,2,3,...$). You are bored and out of the blue you decided to divide golds into groups such as the sums ...
6
votes
14answers
476 views

Mysterious Trams

I ride a tram six stops to work. I don't worry about the time or check a clock: I just go to work when I'm ready to go, and go home when I'm done for the day. Never at set times. Each tram line ...