r/puzzles

This thread is for promoting your own work.

A sultan captured 50 wise men. The sultan decided to play a game with the men to decide whether they would live or be executed.

Here's how the game goes. The men will be locked in 50 different cells, completely separated from each other. Every minute, the sultan calls a man randomly. Each time, the called man has three choices. He can either flip the glass cup the sultan has placed at the start of the game, leave it as is, or ask permission to leave. If a man asks permission to leave and the sultan has called every one of the 50 men at least once, they will all be spared and freed. If not, they will be executed. The glass placed at the start of the game is bottom-down.

The men cannot tell the time in their quarters, there's no other way to convey information to another man except through flipping the glass, and the sultan's calling is perfectly random every time.

The men are given time to discuss their strategies before being sent to their cells. What should they do in order to ensure their survival in the shortest time possible?

EDIT: The wise men will all take a good look at the glass and its initial position before starting.

Here's a simple puzzle that might be trickier than meets the eye.

Consider the four-letter word MEAT. If you remove the first letter, you get the three-letter word EAT, which is nesting withing the word MEAT. Likewise, if you remove the second letter, you get the three-letter word MAT. And if you remove the third letter, you get the nesting word MET. However, if you remove the fourth letter, you get MEA, which isn't a common three-letter English word.

Here's the puzzle: can you identify a four-letter word where all four or its nesting three-letter words are also valid words? All of the words must be common English words. They cannot be proper nouns (such as Lou), abbreviations (such as E.S.T.), or partial words like prefixes or suffixes (like NEO-). If a common dictionary (like the Oxford English Dictionary or the Merriam-Webster dictionary) says it's a stand-alone word in English, that's sufficient.

It's trickier than you might think. As an extra challenge, see if you can do it using only raw brain-power (as opposed to, say, some sort of computer program).

To prove it's possible, here's a solution that I was able to find. >!BOAT!< has four nesting words: >!BOA, BAT, BOT, and OAT!<. Another possible solution is >!FOUR!<, with the nesting words >!OUR, FUR, FOR, and FOU (an obscure word in the Oxford English Dictionary meaning "drunk" or "intoxicated")!<. Can you find any others? Happy solving!

I'm pretty sure everybody has heard of the angel and devil riddle. It contains an identical looking devil and angel guarding two doors. The angel will always tell the truth, and the devil will always lie. You must ask one question to discover which door leads to heaven (The angel isn't necessarily guarding the door to heaven).

In case you haven't, here's the answer:

>!Ask either of the guards "If I asked the other guard if the left door leads to heaven, what would he answer?" This phrasing allows the question (whether the left door is the heaven one) to go through both guards, always resulting in a lie. Therefore, if he answers yes, take the right door. If he answers no, take the left door. !<

This is a twist in this classic puzzle: two doors, one guard. The guard is either an angel or a devil, but you do not know which.

The language of heaven and hell is apparantly the same, and different from your own. They can only answer "ALA" or "ULU", which stands for yes or no, but you do not know which is which. The angel or devil in question can understand your language, but they will only answer in their own.

You have one question. What question do you ask to find out which door leads to heaven?

Design a coin toss game using only one coin where the chances of your winning is exactly 1/3.

The coin throw will always result in heads or tails, and will be 50:50.

For example, if the game is: "I win if the toss results in heads", My chance of winning is 1/2.

EDIT: It's a little too easy with "normal" rules. If possible, try to summarize the answer into a clear mathematical condition, like the example above.