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1500 questions
25
votes
2 answers
Who killed Professor Cal?
Professor Cal was found murdered in his office. Luckily, security had been keeping tight track of all who entered and exited the building during the day, and were able to determine that the suspects are Gerry, Julie, Jason, Nicky, and Sophy. …
Aggie Kidd
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25
votes
4 answers
Which is larger? $\sqrt{15} - \sqrt{7} + \sqrt{5} + \sqrt{2}$ versus $5$
Which side is larger?
$$ \sqrt{15} - \sqrt{7} + \sqrt{5} + \sqrt{2} \stackrel{?}{\lessgtr} 5 $$
Without using a calculator, computer, or estimating square roots, please
determine which side has the larger value.
Rules of the game:
In this…
Olive Stemforn
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25
votes
2 answers
Rooks on a 15x15 chessboard
On a 15x15 chessboard there are 15 rooks that do not attack each other (via ordinary rook moves). Then each of the rooks makes one move like that of a knight.
Is it possible that after all this is done, the 15 rooks still do not attack each other…
D.A.G.
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25
votes
9 answers
Computer riddle: I treat vars like D
Little 'bout my age: far from that of B
Yet in my syntax, you will find some C
The way I treat vars, that is much like D
I do take objects, but I'm not like E
If it starts with F, you'll know it's not me
Now I challenge you, just what could I be
I…
busukxuan
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25
votes
2 answers
Desegregate the Knights
You are given a 3 by 3 chessboard with a knight on each corner, where the knights in the top row are black and in the bottom row are white.
On each turn, you may move a knight of either color (the way it moves in chess) to an unoccupied square.
Is…
Mike Earnest
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25
votes
3 answers
In the iterated Prisoner's Dilemma, how would a change in the payoff matrix affect strategy?
Quick summary of the Prisoner's Dilemma: Two criminals are charged with a crime. Each is given an opportunity by the police to confess.
If they both stay silent, they don't have enough evidence to convict for much, and they both get 1 year in…
durron597
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25
votes
3 answers
Rainbow Road Rabbit Hole
Question: Who is in first place?
It's difficult to add hints in the puzzle itself given its nature so I'll try to add some notes here as text instead.
Red: [Solved]
Orange: [Solved]
Yellow:
K1
Engineer Toast
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25
votes
1 answer
Four is Cosmic!
This is a little puzzle I heard a while back from one of my mathematically inclined friends- I get the sense that it's bounced around a little, so forgive me if you've heard it.
There is a sort of function that, given any positive whole number, will…
Patrick N
- 1,790
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25
votes
5 answers
How much red sand and how much blue sand?
This is a puzzle I remember arguing with my sister about when we were little...
(Not quite as loud (or as public!) as the Monty Hall argument we had.)
You have two large beakers of the same size.
Beaker A is half filled with blue sand.
Beaker B is…
Ali
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25
votes
1 answer
Create a Word Search
Create a word search with the following conditions:
Use the eleven words below. They can be spelled up, down, left, right, or any of the 4 diagonal directions.
ZERO
ONE
TWO
THREE
FOUR
FIVE
SIX
SEVEN
EIGHT
NINE
TEN
The size…
JLee
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25
votes
1 answer
Six-words (------) Six-words (||||||)
Six-words:
My first is what a bouncer does if they think you're cool enough
My second is what my fourth does to your pain
My third is your surroundings on a grassy hill in summer
My fourth is taken to do my second to your pain
My fifth…
Engineer Toast
- 17,506
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25
votes
13 answers
3 Planks, 1 nail
John and Bob were doing some home construction and decided to take a beer break. Before grabbing a seat John pulls out 3 planks of wood, 1 nail and a hammer. John makes a bet with Bob saying
I'll bet you a beer you can't make a triangle given just…
Mark N
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25
votes
4 answers
Am I a sailor or a bunny?
When I am blue, you can drink me
When I am red, I'll disappear
I have serenity and cleverness
But I become a wolf if you double me
I have only 12 friends
But I haven't seen them in a while
Who am I?
A.D.
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25
votes
4 answers
King Octopus and Servants Puzzle
Puzzle:
King Octopus has servants with six, seven, or eight legs.
The servants with seven legs always lie, but the servants with either six or eight legs always say the truth.
One day, 4 servants met:
The blue one says: “Altogether we have 28…
Saurabh Prajapati
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25
votes
4 answers
What screams from the ears and listens from the mouth?
I have ears but failed to listen
I have mouth but failed to scream
but good thing!
I have ears to scream
I have mouth to listen
Dyrandz Famador
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