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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).

-1
votes
1answer
56 views

Mystic Island Math - Can you Figure it out?

On Mystic Island math is done via symbols. Distinct symbols represent distinct digits, varying from 0 to 9. From the picture below, figure out the corresponding digits. Please provide your reasoning....
-4
votes
2answers
91 views

How do you Solve an Age-Old Problem? [on hold]

Mansion has a son (Mark) and a daughter (Mindy). Mark is older than Mindy. Five years ago, Sum of Mark and Mindy’s ages was twenty two. Five years from now, Mark will be exactly twice as old as Mindy....
1
vote
3answers
124 views

Jack and Jill went up the Hill to play

A Simple Card Game. This deck of cards has only four cards simply labeled 1, 2, 3, 4. They are placed face down. Jack and Jill take turns to draw a card. You sum up the numbers drawn so far after ...
8
votes
1answer
166 views

Riddle to Code 2: The return of numbers

The first is a pirates favorite letter. The second is from a famous quote of shakespear. The third is squaring it off in a famous formula. The fourth is the first in a very well known song. ...
-5
votes
1answer
75 views

Express 50 to 100 with constituent digits only…my 100th pzl on 50th day

Using the following rules only, Express the numbers from 50 to 100 using only digits in the number. Concise with minimum number of characters is preferred. No concatenation of numbers allowed. Only, ...
2
votes
2answers
113 views

Find the “X “in the Box

Interlocked Rings shown in the picture share a common sum of 28. The numbers to be filled vary from 1 to 12 and do not repeat. Already four numbers..8, 9, 10, 11 are placed. Fill the X s with rest ...
9
votes
3answers
4k views

Too early in the morning to have SODA?

Each letter shown represent distinct digit...can vary from zero to nine. $COCA$, $COLA$, $SODA$ are three concatenated numbers. Figure these out from the following relation: $COCA + COLA = SODA$
18
votes
5answers
4k views

Can you open the door or die? v2

This is the follow up question to my previous question You wake up and find yourself in a very strange room with a single door. You find a note on the ground surrounded by lots of cards: ...
2
votes
2answers
74 views

All the Signs point to the Second Prime…Figure out the Missing Digits

$Given$ The six Interrelated Equations A, B, C, D, E, F All equal to 3. Allowed Digits.. 1 to 9. All the missing 9 are distinct...9?s...9 Different Digits Fillin all the digits that satisfy all ...
2
votes
3answers
186 views

16 people, make 3 consecutive round of 4 players

I am struggling with this issue for a tournament I am planning. Take 16 people. Consider a 4-player game. To be clear, in each round all 16 players must play the game once. I want to make at least 3 ...
10
votes
4answers
2k views

Can you open the door or die?

You wake up and find yourself in a very strange room with a single door. You find a note on the ground surrounded by lots of cards: There are 66 green and 66 blue door cards on the ground. If you ...
8
votes
1answer
662 views

I am caught when I was about to steal some candies

I am a eight years old boy, I love candies, but my mom does not want me to eat any more candies because I start to have black teeth :( but I still love candies so... Today when I was about to steal ...
3
votes
2answers
358 views

Is it True that Two + Two = 2? If so, what is Ten + Ten and Nine + Nine?

Given: SIX + ZERO = 4 TWO + THREE = 15 FIVE + SIX = 88 ONE + TWO = 83 TEN + TWO = 13 If so, is TWO + TWO = 2 correct? What is TEN + TEN ? NINE + NINE ? Hint 1
14
votes
3answers
7k 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 ...
5
votes
2answers
151 views

Please figure out this Pan digital Prince

Given: P, R, I, N, C, E, T, O, M are all distinct digits varying from 1 to 9. PCRON, PRINCETOM are two concatenated numbers. PCRON is the highest possible number you can have fulfilling the ...
4
votes
3answers
92 views

Make 2019 Factorial Multiplication a perfect square

N is not a square number and consists of 2019 factorial multiplication as shown below: $N=1!\times 2!\times 3!\cdots 2018!\times2019!$ At least how many factorial needed to be removed from the ...
10
votes
1answer
227 views

Next date with distinct digits

The date today is 7th June 2019, or 07/06/2019 (using the English DD/MM/YYYY ordering). When is the next date that when written in this way has all eight digits different?
11
votes
3answers
356 views

Masyu puzzles with many circles

The rules of Masyu: Make a single loop with lines passing through the centers of cells, horizontally or vertically. The loop never crosses itself, branches off, or goes through the same cell ...
0
votes
1answer
126 views

Don’t let this daunting equation dissuade you to deduce the desired result

Given: A, B, P are distinct digits. AA, AAA, ABB are concatenated numbers. Relations: $$P=A+A+B$$ $$(AA + ABB)^P-(ABB)^P=(AAA - A) ^P+(B+B^B*B)^P+(B^B)^P$$ Don’t be afraid to make reasonable ...
9
votes
2answers
558 views

Six liars, truth-tellers and jokers

As in this puzzle, there are three different kinds of people: truth-tellers (always telling the truth), liars (always lying) and jokers (who may either tell the truth or lie). Based on these aspects ...
6
votes
2answers
282 views

$1$ of $100$ Homes

On Crossfield Housing Estate, there are exactly $100$ homes numbered from $1$ to $100$. Rook is living in one of them. Kaito hasn't met with him for a long time and wants to pay a visit. Here is some ...
33
votes
9answers
4k views

Winning Strategy for the Magician and his Apprentice

There are $13$ upside-down opaque cups and $2$ balls, a magician and his apprentice and yourself. You decide under which cups to put the balls, and the objective of the magician is to find the two ...
2
votes
1answer
124 views

A $3\times3$ ColorSaw

The pieces of this ColorSaw have been flipped, rotated and moved. Can you reassemble the puzzle so that each adjacent side has the same color/shape?
0
votes
2answers
118 views

A $2\times2$ ColorSaw

The pieces of this ColorSaw have been flipped, rotated and moved. Can you reassemble the puzzle so that each adjacent side has the same color/shape? Please explain your logic!
-2
votes
1answer
162 views

The Guys - Logic #1 - Comics

Welcome to the first in a series of quick logic puzzles. The stories behind the puzzles follow 3 guys who are life long friends, went to school together, and now work in the IT field together in Tampa....
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votes
1answer
105 views

The Guys - Logic #2 : Ways to work

So the guys are back. This time, they decide to change up their way to work. Let's see what they're up to... Start the two minute timer... 1. Since Anthony and Charles weren't taking the bus today, ...
-7
votes
2answers
166 views

The Guys - Logic #3 - The Casino

Oh boy, the guys went to the casino.. Let's see what these three are up to tonight. I wonder if going to the casino was a good idea?? Maybe for a couple of them. Start the two minute timer... The ...
9
votes
2answers
291 views

Generating different difficulties in custom puzzle

first of all this is my first time asking something here so please let me know if I am doing something wrong or asking it on the wrong place. I have a custom puzzle model where I need to generate ...
2
votes
1answer
161 views

Solve the pattern! (game)

Okay, so this is based off of https://www.chiark.greenend.org.uk/~sgtatham/puzzles/js/pattern.html And, my cousin made a random pattern and gave it for me to solve. Unfortunately, the logic is ...
9
votes
3answers
578 views

A Mathematical Discussion: Fill in the Blank

I originally saw this on r/puzzles, and thought it deserved a place here. I have a solution to this puzzle, but it's really long and ugly. If anyone comes up with something simple, please share! ...
3
votes
1answer
215 views

Happy New Year?

Extend this infinite series by five more terms: 17, 3, 5, 7, 11, 17, 2, 3, 5, 11, 13, 17, 2, 5, 7, 11, 13, 2
18
votes
2answers
304 views

Statue View: Tetrominoes

This is a Statue View puzzle, an original invention combining two logic puzzle genres: Statue Park and Canal View. Rules of Statue View: Shade some cells of the grid to form the given set of pieces. ...
12
votes
1answer
379 views

Infinite Sequence based on Simple Rule

Using one simple rule, an Infinite Sequence has been developed. First 30 terms are given. Can you continue the sequence for at least next Ten Terms? Series continues from top left to bottom right. $...
0
votes
4answers
6k views

Four boys and four girls

Four boys and four girls go to a movie theater to see a movie. All the boys sit together and all the girls sit together. All the boys and girls are sitting in 8 adjacent seats. After some time, the ...
0
votes
2answers
131 views

Do you know what's next?

'Predict' the next few (5 or 6) terms of this series. 1, 1, 1, 2, 3, 6, 7, 10, 11, 12, 17, ...? Hint: Who is the 'prime' suspect in this mystery sequence?
12
votes
1answer
224 views

Statue View: 2, 3, 5, 7

This is another Statue View puzzle. It's easily the hardest of the three I've made, so I recommend trying the other two as practice first. Rules of Statue View: Shade some cells of the grid to form ...
12
votes
1answer
221 views

Statue View: Raindrops

This is a Statue View puzzle, an original invention combining two logic puzzle genres: Statue Park and Canal View. It is harder than my previous Statue View, so you may want to start there. Rules of ...
1
vote
1answer
125 views

Mensa 3rd Grade Recess Game [closed]

Mensa 3rd Graders At Recess There are dozens of variations of this puzzle type, but I put my own spin and characteristics to it. It is lunch time for the little ones at Mensa Mini's Private School. ...
6
votes
2answers
196 views

Liars, truth-tellers and jokers

In a strange village there are three kinds of persons: knights (always telling the truth), knaves (always lying) and jokers (who may either tell the truth or lie). A, B, C and D live in this village, ...
15
votes
1answer
464 views

Statue Park: Knight's Lines

This is a Statue Park puzzle. Rules of Statue Park: Shade some cells of the grid to form the given set of pieces. Pieces may be rotated or reflected. Pieces cannot be orthogonally adjacent (though ...
6
votes
1answer
345 views

The Most Powerful Number

A power-full number is defined as a number with $n$ amount of non-zero digits $D_x$. The number takes the form $D_n$&$...$&$D_2$&$D_1$. The digits in a power-full number satisfies the rule ...
28
votes
3answers
3k views

12 Birds in the petshop

You decided to buy 2 birds from a pet shop and went to a pet shop for it. There are 12 budgerigars at the pet shop and you want a male and a female for your home. You cannot distinguish the gender of ...
1
vote
2answers
317 views

Placing rooks on a chessboard

We have a big chessboard with N rows and N columns (numbered 1 through N). Let's denote the square in row r and column c of the chessboard by (r,c). We want to place some rooks on the chessboard in ...
2
votes
1answer
99 views

Puzzling Palindromic Year with Pleasing Palindromic Expression.. Please find them

No computers, calculators or searches. Given: The number is a Palindromic year. $PQ$ is a concatenated number. $ U , V $ are two distinct positive integers Expressed as $ PQ ^ U + PQ ^ V + ...
4
votes
1answer
201 views

Four Doors, One Escape

You are trapped in a room with four adjacent doors upon a wall. On each door is one of the first letters of the alphabet, in order, from left to right. You know that one of the doors leads to freedom, ...
7
votes
3answers
600 views

Three knights or knaves, three different hair colors

In a group of three people (A, B and C), everyone has a different hair color (blond, black or brown, not necessarily in this order) and everyone may be either a knight (always telling the truth) or a ...
7
votes
1answer
256 views

Statue Park: Five

This is a Statue Park puzzle (originally constructed for the 2019 24-Hour Puzzle Championship, as part of a Tarot card themed set -- no prizes for guessing which rank this puzzle was). Rules of ...
0
votes
2answers
83 views

Uvc with Lots of Magic… Enjoy the Show!

Puzzling Weekend! UVc is back again with Lots of Magic... Enjoy the Show! Given: LOTS is being multiplied by F to yield MAGIC. Digit 0 to 9 are all represented by ten different letters in this ...
3
votes
2answers
129 views

Find the values of U, V, C based on the given relationship…useful for upcoming puzzles

Given: U, V, C are 3 distinct digits..values can vary from 1 to 9. CU is a concatenated number Solve for U,V, C from the following relationship: $U^V$ X $V^U $ = $CU $ This will give some basis ...
2
votes
2answers
181 views

Cathy’s Composite party is powered by three Prime Pals. Can you find them?

Given: A, B, C are 3 distinct primes. Find the smallest composite number Y that satisfies the relation: $ Y = A ^ C + B ^ B + C ^ A $