Alien abduction brain teaser | Puzzles | Math for fun and glory | Khan Academy

TL;DR

Ten people are chosen by aliens to represent humanity, and they must come up with a system to determine the color of hats on their heads to save their lives and prevent Earth from becoming a mushroom farm.

Transcript

Ten of us have been abducted by aliens because they view us as being representative of the human race. And what they're going to do is they're going to test us to see if the human race is worthy of joining the intergalactic council of planets. And if we're not, they're going to kill us all and and turn Earth into a mushroom farm, because that's the... Read More

Key Insights

• 🤠 The group of ten individuals must determine the color of their hats in a pitch-dark room to save their lives and the fate of Earth.
• 🥰 They must come up with a system within 24 hours to indicate the color of their hats, relying on the information they hear from others in the dark room.
• 💚 The person in the back counts the number of green hats they see in front of them and will say "green" if the count is odd, or "purple" if it is even.
• 💁 Each subsequent person uses the information they hear to deduce the color of their hat and say it aloud.

Questions & Answers

Q: How many people are selected by the aliens to represent humanity?

Ten people are chosen to represent humanity and determine the color of their hats to save their lives and prevent Earth from turning into a mushroom farm.

Q: What information is provided to the group by the aliens?

The aliens inform the group that they will be placed in a completely dark room and given a hat on their heads, which can either be purple or green. The distribution of hats will be random, and each person can only say "purple" or "green" to indicate the color of their own hat.

Q: What happens if a person guesses the wrong color of their hat?

If a person guesses the wrong color of their hat, they and the people they represent will be displaced, and their land will be turned into mushroom farms.

Q: How many people can the group guarantee to save?

By implementing a specific system, the group can guarantee to save nine people out of the ten representing humanity.

Summary & Key Takeaways

• Ten people are selected by aliens to represent humanity and are told that their fate and the fate of Earth rests on their ability to determine the color of their hats in a pitch-dark room.

• The aliens will randomly distribute purple and green hats on their heads, and each person can only say "purple" or "green" without any intonation or additional information.

• The group must come up with a system to save as many people as possible by using the information they hear from others.