TED-Ed RIDDLES

Oct 5, 2015

You and nine other individuals have been captured by super-intelligent alien overlords. The aliens think humans look quite tasty, but their civilization forbids eating highly logical and cooperative beings. Unfortunately, they’re not sure whether you qualify, so they decide to give you all a test. Can you solve this hat riddle? Alex Gendler shows how.

Feb 1, 2016

Your expedition finally stands at the heart of the ancient temple. But as you study the inscriptions in the darkness, two wisps of green smoke burst forth. The walls begin to shake. The giant sandglass begins flowing with less than an hour before it empties, and a rumbling tells you that you don’t want to be around when that happens. Can you use math to escape the temple? Dennis E. Shasha shows how.

Feb 29, 2016

You’re stranded in a rainforest, and you’ve eaten a poisonous mushroom. To save your life, you need an antidote excreted by a certain species of frog. Unfortunately, only the female frog produces the antidote. The male and female look identical, but the male frog has a distinctive croak. Derek Abbott shows how to use conditional probability to make sure you lick the right frog and get out alive.

May 1, 2017

It’s a good day to be a pirate. Amaro and his four mateys – Bart, Charlotte, Daniel, and Eliza have struck gold – a chest with 100 coins. But now, they must divvy up the booty according to the pirate code — and pirate code is notoriously complicated. Can you help come up with the distribution that Amaro should propose to make sure he lives to tell the tale? Alex Gendler shows how.

Jun 26, 2017

As the cargo director on the maiden voyage of the S.S. Buoyant, you’ve agreed to transport several tanks containing the last specimens of an endangered fish species to their new aquarium. Unfortunately, the boat is battered by a fierce storm, throwing your precious cargo overboard. Can you get the fish to safety and save the day? Steve Wyborney shows how.

Jun 4, 2018

After months of travel, you’ve arrived at Duonia, home to the famous temple that’s the destination of your pilgrimage. The walk from the welcome center to the temple isn't a long one ... but there’s a problem. Can you outsmart the city's imposed tax and make it to the temple without paying a fee? Daniel Finkel shows how.

Mar 22, 2018

After a massive storm tears through the Hex Archipelago, you find five grizzled survivors in the water. As an act of gratitude for saving them, they reveal a secret – the island they were just on holds some buried treasure. But when the sailors try to describe the island, something seems off. Can you find the booty despite their strange instructions? Daniel Griller shows how.

Oct 9, 2018

The good news is that your experimental robo-ants are a success. The bad news is that you accidentally gave them the ability to shoot deadly lasers … and you can’t turn it off. Can you stop them from escaping their habitat before the lasers are activated? Dan Finkel shows how.