All Questions
Tagged with hat-guessing mathematics
17
questions
10
votes
1
answer
990
views
Guess color of your hat cooperatively, goal is all correct or all incorrect [duplicate]
Let n be an integer. n logicians standing in a circle are blindfolded and a hat of either red or blue is put on each person's head. Blindfolds are then removed; each person can now see the color of ...
- 103
-1
votes
1
answer
175
views
Hat and Earring Guessing Puzzle, with penalty for passing
You are in the final round of a game show with 3,999 other conteseants.
Here is the game: The host has blindfolded you at put a red, green or blue hat and red, green or blue earrings (not necessarily ...
- 1,130
-2
votes
1
answer
419
views
Infinitely many deaf dwarves
A beautiful puzzle, and I know the solution. I read it on an Italian riddle forum.
An evil witch kidnaps infinite (countable) dwarves. The witch tells the dwarves that the next day she will put them ...
- 317
4
votes
2
answers
778
views
3 hats with numbers, where 2 hats sum to the third
I have outlined a puzzle below, and provided two sources which provide answers. I am disputing that the answer provided in the sources is correct, and I am looking for others to validate or invalidate ...
- 171
8
votes
2
answers
487
views
Modifying the puzzle: Cooperative hat-guessing, no mistakes, 3+ colors
Following Guess your hat color, but you don't have to and it's interpretation via Covering codes I tried to create a puzzle with more hat variativity, i.g. 3 types of hats.
4 hats are put on 4 ...
- 16.3k
8
votes
3
answers
741
views
Guess your hat color, but you don't have to
Here is the puzzle:
N hats are put on N logicians, each hat color is selected randomly: black or white.
As usual, every logician doesn't see the hat on his own head, but sees the rest. They cannot ...
- 16.3k
4
votes
1
answer
219
views
What is my number in circle? [duplicate]
N > 1 people sit in a circle clearly seeing all others. They are going to be blindfolded and, while in this state, hats are put on their heads - one per person, naturally. On each hat there is written ...
- 41
7
votes
3
answers
1k
views
Guess simultaneously, color of your hat, no passing allowed
1000 logicians standing in a circle are blindfolded and a hat of either black or white color is placed on each person's head. The blindfolds are then removed and each person can now see everybody's ...
- 3,343
23
votes
3
answers
4k
views
3 Numbers on Hats, A = B + C
This feels like it should be a common puzzle, but I haven't found anything exactly like it searching online, so here goes. Apologies if it's a duplicate.
Three logicians, person 1, 2, and 3, along ...
- 397
12
votes
3
answers
2k
views
A hat puzzle involving wizards
Two wizards, Alice and Bob, each have two hats on their heads. Each hat is independently black or white with probability one-half. When the game starts each wizard will see the hats on the other ...
- 7,845
7
votes
3
answers
1k
views
Surviving Captain Nefarious
Captain Nefarious has captured you and two of your friends, Alice and Bob. Being a villain, he has a natural desire to monologue, so he sits you down (guarded, of course by his Largely Incompetent ...
- 26.4k
8
votes
1
answer
633
views
One hundred and one hats
You are a prisoner. One day, the Warden summons you and ninety-nine others to see his hat collection.
"Bowlers and baseball caps. Stensons and sombreros. One hundred and one headpieces, each unique ...
- 9,564
15
votes
3
answers
1k
views
100 Dwarves vs. the Evil Elf
The following is an extension of 100 Dwarves and a tiny room. The text of this puzzles spoils that one in a minor way, so go read that excellent puzzle first!
An evil elf puts $100$ dwarves in a ...
- 9,564
19
votes
6
answers
3k
views
Cooperative guessing game: no incorrect guesses
There are 15 players who will play a cooperative game. They begin by closing their eyes. A referee will place either a black hat or a white hat (chosen by fair coin flip) on each player's head. The ...
- 14.3k
6
votes
2
answers
753
views
N people, N hat colors, and a One-Way Glass
This is a variant of this question, reproduced below:
There are $n$ people, who will stand in a circle while a game master places a hat on each of their heads. The hats can each be one of $n$ colors (...
- 32.5k