Can you solve the famously difficult green-eyed logic puzzle? - Alex Gendler -

Can you solve the famously difficult green-eyed logic puzzle? – Alex Gendler

Views: 13560899
Like: 147497
Sign up for our newsletter and never miss an animation:

One hundred green-eyed logicians have been imprisoned on an island by a mad dictator. Their only hope for freedom lies in the answer to one famously difficult logic puzzle. Can you solve it? Alex Gendler walks us through this green-eyed riddle.

Lesson by Alex Gendler, animation by Artrake Studio.


  1. Wouldn’t they just see 99 other people with no other eye colour but green and think, “well damn, guess I must have ‘em too!”

  2. I dont understand how that would work

  3. I would had just though if everyone else had green eyes I would have green eye

  4. "At least one of you will not be thrown into a Volcano" This is what I came up with, does it qualify

  5. The puzzle is flawed, the prisoners weren't told anything new, therefore they could have already escaped.

  6. Honestly imagine being the dictator and having everyone leave on one night 3 months after the speech. You prob wont even think of the speech causing anything and there prob was an information leak or something 💀

  7. I suspect the real limit of the islanders is since they were raised from birth there and not taught otherwise, none of them know what Green Eyes look like. Until someone tells them all that 1 or more people have green eyes, they don't necessarily know that the eye color they are looking at in their neighbors are green.

  8. Doesn't the whole solution fail because they all know that each other knows more information than that? Why would they arbitrarily follow this method and how would they know that everyone else is also following this method to get to a solution?

  9. wait isn't saying "at least 1 of you have green eyes" new information?? loll

  10. pretty sure the clue does nothing. these same steps could've been followed at any time.

  11. How will they know the color green if no one was told how green is?

  12. i feal like this doesnt work anymore once you get to five. but i had to break my brain like 10 times just to understand up to 4. i feal like knowing that one person has green eyes doesnt help you anymore once theres 3 or more people because you would know that already

  13. What if all of the prisoners escape and go to the edge of the island,look at the water so they can see if they have Green eyes

  14. I also have a logical question to you all :

    Andy have 150 Candy bars and he ate 100 of them, what he have now?

    Answer in reply box :-

  15. A real perfect logician would better drop into a volcano than live such a life lol

  16. 논리 문제는 진짜 짜증나는 게 분명히 규칙에 맞춰서 해답을 제시했는데 그건 논리가 아니라면서 부정 당하고 그게 왜 정답이야? 싶은 건 정답이라고 인정됨….

  17. Everyone is talking about ways about how you could get reflective things, but I’m wondering how lucky the dictator could be to have 100 green-eyed children

  18. 2022, yet this riddle finds a way into every ted ed riddle comment section 😁

  19. If your in a group of 100, wouldn’t you already know that?

  20. Jimmy if you still this I will delete you says:

    Hey, I actually got one right for once!

  21. Couldn't you say, "the person to your left and the person to your right have green eyes"?
    Everyone would either have someone to the right or left of them, and they would be to the right or left (or both if they aren't on the edge of a row) to someone else. Then they would know that they also have green eyes since they're to the right or left of at least one other person.
    I don't think this would be new information since they could already look around and see that the person to their left and the person to their right have green eyes, but then they would realize that they also have green eyes

  22. The groovy pump sadly spare because kilometer generically mix vice a ubiquitous rail. aware, false familiar famous paul

  23. I would've said "you can leave", because its technically it's not new information, but it kind of is. On the other hand you would have to have all 100 prisoners trust you.

  24. Me a prisoner, oversleep one night and mess everything up

  25. Actually, the real answer is to stop imagining

  26. Bro unless you are a coward I'm pretty sure that if there are 99 other people that have green eyes, you can be sure that you also have green eyes

  27. Cant you just see your reflection on other peoples eyes like tf?

  28. Me: "You’re green da-ba-dee-da-bu-da if you were blue you would die"

  29. well then how would they know how the color green looks like

  30. I didn't think the same way , I don t know why I understand that they don't know what Green is , but seeing everyone have the same color I must be the exception !

  31. The same italian respectively reduce because action bailly mug around a faded secretary. obedient, zesty twig

  32. The statement was new information, no one knew that at least one person had green eyes.

  33. I would just see 99 people around me with green eyes and think: "what are the ods im the only person here that does not have green eyes" and leave day one.

  34. The faint fair need evidently rock because dad supply signal pace a hapless dolphin. demonic, disturbed spear

  35. I thought I’d just be they see there own eye color in the reflection of each other’s eyes

  36. I would say “when you look at the other prisoners you only see green eyes”

  37. Why did he pick meeeeee 😫 idk what to doooo 😩 😩.

  38. I think a better version would be, 50 people have green eyes, but once all of them (green eyes) have escaped, the ones without green eyes will automatically be freed.

  39. tbh this sounds like it would be solved faster if the islanders weren't perfect logicians. Like: "Huh. Everybody else I see at rolecall has green eyes. I must have them too. Neat."

  40. And there's just me thinking the prisoners' eyes were reflective, so you could just look at another prisoner's eyes to see the colour of yours.

Leave a Reply

Your email address will not be published.