The Puzzle Thread

[leonid]

Numbers on the choices matter and solutions can vary depending on them.

In our particular case, there's one solution

[Reincarnate]

What does the fox say

[___________]

sum up P(correct answer is " ") * P(" " was chosen), you get 1/2*1/2+1/4*1/4+1/4*1/4 = 3/8

my thoughts

EDIT: didn't realize the choices referenced themselves

[Evnoir]

Originally Posted by ___________

sum up P(correct answer is " ") * P(" " was chosen), you get 1/2*1/2+1/4*1/4+1/4*1/4 = 3/8

my thoughts

Depending on how the question is interpreted, I was also thinking that or

1/3*(1/2+1/4+1/4) = 1/3
or with the differently weighted answers: 1/2 and 1/4.

I'll just stick with 0 still since it seems to make the most sense

[leonid]

It's nothing complicated

Answer is 25% -> 50% chance to get it right by guessing (=Answer is 50%) -> Contradiction
Answer is 50% -> 25% chance to get it right by guessing (=Answer is 25%) -> Contradiction
Answer is 60% -> 25% chance to get it right by guessing (=Answer is 25%) -> Contradiction
Answer is anything else that is not 0% -> 0% chance to get it right by guessing (=Answer is 0%) -> Contradiction

We only have 0% left as a candidate for the answer, and if the answer is 0%, the chance to get it right by guessing from the given choices is 0%, which satisfies the condition. Hence the answer is 0%

There's a variation where the choice C is 0% instead of 60%. For this variation, there is no solution

[Zapmeister]

here are two more silly puzzles to kill your time

(1)

+-------+-------+-------+
| . . . | . . 1 | . . 2 |
| . . 3 | . . . | . 4 . |
| . 5 . | . 6 . | 7 . . |
+-------+-------+-------+
| . . . | 8 . . | . 7 . |
| . . 7 | . . 3 | 8 . . |
| 9 . . | . 5 . | . . 1 |
+-------+-------+-------+
| . . 6 | . 8 . | 2 . . |
| . 4 . | 6 . . | . . 7 |
| 2 . . | . . 9 | . 6 . |
+-------+-------+-------+

you are given that there is a unique solution. find it.


(2) (ok i lied this isn't really a puzzle) the answers to the first verse are "no, no, no, no" and the answer to the second verse is "get them yourself". what is it?



hat question

if d looked at b and c's hats and saw they were the same colour then d would know his own hat was the other colour. but d doesn't say anything so c assumes d has a reasonable level of intelligence so that c knows his hat colour is different from b's. that's the answer.

[igotrhythm]

fuck you and your poker/sudoku, Zap :P

There are two poles, each 50 feet high. A 60-foot-long rope of uniform density is strung between the tops of each. The rope dips to a height of 20 feet at its lowest point. Find the distance between the two poles.

[Zapmeister]

Originally Posted by igotrhythm

fuck you and your poker/sudoku, Zap :P

There are two poles, each 50 feet high. A 60-foot-long rope of uniform density is strung between the tops of each. The rope dips to a height of 20 feet at its lowest point. Find the distance between the two poles.

hey what the hell does poker have to do with any of this :P

your question actually got me scrabbling for my first-year variational principles course notes before i realised what you did. har har

[Kotarouchan]

that's a cute one there igot

[Reincarnate]

I have three legs, but cannot stand
I have two eyes, but cannot see
And yet, I can see very far, but nothing can be distinguished
I am constantly starving, yet always full
And if you look for me, I can never be found.

What am I?

[Litodude]

i was told this back in highschool, though i've changed it a bit.

you are stuck in a room.

this room has a door, and a transparent floating screen.

the room is metallic.

the door is metallic. 

the screen is intangible and unbreakable..

the knob is metallic, and has no significant features other than an engraving which signifies the direction in which the knob is to be turned. 

the hinges which the door turns upon, is on the other side, indicating the door is turned away from you.

you are given a lighter. this lighter is unbreakable, and immovable apart from its intended function: to light.

you are given four pieces of string. the pieces of string non-uniformly burn for 30 minutes each. 

you are given a 5x5 cm piece of cloth. the cloth is neatly folded and can fit in between the cracks of the door

you are given a pencil. it is sharpened and #2.

the floating screen indicates: "the door will only open after precisely 45 minutes of time elapses, no sooner, no more - otherwise you are electrocuted  upon twisting the knob. 

your body can only handle two electrocutions before dying. if you cannot exit within 2 hours you will be killed."

it then counts down: 5, 4, 3, 2, 1, GO.

how do you get out?

edit- grmamarrar

[Evnoir]

After you hear GO, take one of the strings and light it at both ends. Precisely after the first string completely burns, light the second string at one end only.
In the mean time, you can take the piece of cloth and write down with your pencil a sudoku puzzle you wanted to solve:

+-------+-------+-------+
| 8 7 9 | 4 3 1 | 6 5 2 |
| 6 2 3 | 5 9 7 | 1 4 8 |
| 1 5 4 | 2 6 8 | 7 9 3 |
+-------+-------+-------+
| 4 3 2 | 8 1 6 | 5 7 9 |
| 5 1 7 | 9 4 3 | 8 2 6 |
| 9 6 8 | 7 5 2 | 4 3 1 |
+-------+-------+-------+
| 7 9 6 | 3 8 4 | 2 1 5 |
| 3 4 1 | 6 2 5 | 9 8 7 |
| 2 8 5 | 1 7 9 | 3 6 4 |
+-------+-------+-------+

While you wait for the rest of the string to burn, you suddenly realize that the solution to igot's riddle was that

the poles are beside each other.

When the second string completely burns out, 45 minutes have elapsed and the door will be open.

Reincarnate's riddle is still boggling my mind.

@Zapmeister: I couldn't solve the puzzle and this post was just more for laughs than for solutions. When I solved for all the potential numbers, there was only one spot (6th row, 8th column) that had 2 possible numbers. All the rest were 3+ so I gave up lol

[Litodude]

gj

[MinaciousGrace]

y do they call it circular logic

[igotrhythm]

Originally Posted by Evnoir

After you hear GO, take one of the strings and light it at both ends. Precisely after the first string completely burns, light the second string at one end only.
In the mean time, you can take the piece of cloth and write down with your pencil a sudoku puzzle you wanted to solve:

+-------+-------+-------+
| 8 7 9 | 4 3 1 | 6 5 2 |
| 6 2 3 | 5 9 7 | 1 4 8 |
| 1 5 4 | 2 6 8 | 7 9 3 |
+-------+-------+-------+
| 4 3 2 | 8 1 6 | 5 7 9 |
| 5 1 7 | 9 4 3 | 8 2 6 |
| 9 6 8 | 7 5 2 | 4 3 1 |
+-------+-------+-------+
| 7 9 6 | 3 8 4 | 2 1 5 |
| 3 4 1 | 6 2 5 | 9 8 7 |
| 2 8 5 | 1 7 9 | 3 6 4 |
+-------+-------+-------+

While you wait for the rest of the string to burn, you suddenly realize that the solution to igot's riddle was that

the poles are beside each other.

When the second string completely burns out, 45 minutes have elapsed and the door will be open.

Reincarnate's riddle is still boggling my mind.

I love how you strung all 3 solutions together like that.

Originally Posted by Reincarnate

I have three legs, but cannot stand
I have two eyes, but cannot see
And yet, I can see very far, but nothing can be distinguished
I am constantly starving, yet always full
And if you look for me, I can never be found.

What am I?

The Ironman Triathlon. Three legs (swimming, biking, running); two I's; sees very far (over 100 miles!); always full (of participants)...but the last line is stumping me.

[Zapmeister]

Originally Posted by Evnoir

+-------+-------+-------+
| 8 7 9 | 4 3 1 | 6 5 2 |
| 6 2 3 | 5 9 7 | 1 4 8 |
| 1 5 4 | 2 6 8 | 7 9 3 |
+-------+-------+-------+
| 4 3 2 | 8 1 6 | 5 7 9 |
| 5 1 7 | 9 4 3 | 8 2 6 |
| 9 6 8 | 7 5 2 | 4 3 1 |
+-------+-------+-------+
| 7 9 6 | 3 8 4 | 2 1 5 |
| 3 4 1 | 6 2 5 | 9 8 7 |
| 2 8 5 | 1 7 9 | 3 6 4 |
+-------+-------+-------+

did you actually spot the clever way to do it or did you cheat

because i'm pretty sure this isn't brute-forceable with pencil and paper within a reasonable length of time

:P

[Litodude]

Originally Posted by Reincarnate

I have three legs, but cannot stand
I have two eyes, but cannot see
And yet, I can see very far, but nothing can be distinguished
I am constantly starving, yet always full
And if you look for me, I can never be found.

What am I?

a smartphone on a charging phone dock with its camera open

[Arntonach]

Originally Posted by Reincarnate

I have three legs, but cannot stand
I have two eyes, but cannot see
And yet, I can see very far, but nothing can be distinguished
I am constantly starving, yet always full
And if you look for me, I can never be found.

What am I?

Sums up my stepdad pretty well lol

Gonna take a stab at this and say yatagarasu?

[FoJaR]

ravensburger

[LongGone]

Here's a puzzle from one of my favourite puzzle books:

=========================
A few years ago, I did an experiment on four men in a room. Each men are presented four cabinets containing there drawers each. They are told that in each drawer there is either an apple, or an orange. The men are also told that one cabinet contained three apples, one contained three oranges, one contained two apples and an orange, the final contained an apple and two oranges.

Four labels labelled AAA, OOO, AAO and AOO (for Apple and Orange respectively) are placed on the four different cabinets. The men are told that each cabinet's label are wrong. The men are assigned a cabinet each, and each man cannot see the other men's labels. The men then can open two drawers from his cabinet and try to guess the content of the third drawer.

I couldn't remember exactly the contents of each drawer, as my assistant was the one who prepared them. So I challenged myself to guess the contents based on what the men said.

The first man opens two drawers and says "I see two apples - and I know what's in my third drawer". The second man opens two drawers and says "I see an apple and an orange - and I know what's in my third drawer".

The third man said "I see two oranges - and.." but alas, I can't remember if he said he could tell the contents of his third drawer. He did say yes or no however, and based on that I could figure out with 100% certainty the contents of all four cabinets and what labels were on them.

Can you?
=========================