One of the most popular puzzle genres involves a group of people wearing colored hats.
It has hundreds of possible setups.
Sounds like a wholesome party game, yet the penalty for failure always involves slitting throats or eternal imprisonment.
Photo: Maryna Babych (Shutterstock)
Ive given two hat puzzles below.
The first is a classic and an absolute gem of puzzledom.
Start the rebel uprising, and may the odds be ever in your favor.
Graphic: Jack Murtagh
Did you miss last weeks puzzle?
Check it outhere, and find its solution at the bottom of todays article.
Be careful not to read too far ahead if you havent solved last weeks yet!
Puzzle #48: Hat Trick
1.
Ten friends, er, I mean terrified prisoners, are lined up.
Everybody receives a hat that is either red or blue.
Everybody can hear other peoples shouts.
(No poking the person in front of you, no shouting in an accent, nothing.)
You may assume that everyone cooperates with the groups plan.
What is the maximum number of people that the group can guarantee succeeds?
(Not probabilistically).
Oh, and anyone who fails will be drawn and quartered.
The same exact setup as puzzle 1, but with two wrinkles.
Second wrinkle: people can say pass.
If anybody guesses an incorrect color, then they all lose.
If everybody passes, then they all lose.
They all win if at least one person guesses a color and all guessed colors are correct.
What strategy maximizes their chances of survival?
Ill be back Monday with the answers and a new puzzle.
Do you know a cool puzzle that you think should be featured here?
Shout-out to Veronica, who emailed three correct answers complete with a family tree spreadsheet.
Who is in the photograph?
The man is looking at a photo of his son.
A girl has an equal number of brothers and sisters.
But each of her brothers has only half as many brothers as sisters.
How many kids are in the family?
The family has seven kids: four girls and three boys.
Each girl has three brothers and three sistersan equal number.
But the boys in the family each have four sisters and only two brothershalf as many.
How is this possible?
If youre not sure whos who, the family tree below should help you trace through the relationships.
The two mothers refer to the grandmother and the mom, etc.
News from the future, delivered to your present.
But what if you’ve got the option to play for both sides?
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