We’ve been presented with pictures asking us to spot ballerina amongst a crowd of flamingos, been baffled by photos containing hidden babies, and tried our hand at cracking the world’s hardest word search.


Give them a go yourself here…


So, we couldn’t resist giving the ‘hardest logic puzzle ever’ a go! Published by Ted-Ed, the riddle was created by logician Raymnd Smullyan and popularised by George Boolos.

The explanation of the puzzle is a little complicated, but Alex Gendler explains it clearly in the riddle below. Watch the video to listen to the logic puzzle laid out for you. But, don’t listen beyond 1:13 – otherwise you may find out the answer before you’ve had time to think!

As far as hard logic puzzles, it’s certainly up there with the trickiest to solve!

Stranded on an alien planet, your only chance of getting back to earth again is to present three alien overlords with the correct corresponding artifacts. Sounds straight forward so far right? Well, it gets harder! You don’t know which alien is which, and you only have three chances to ask questions to work it out! The questions also need to have ‘yes’ or ‘no’ answers. Plus, to make it EVEN harder, you don’t know which of the words ‘ozo’ and ‘ulu’ means yes and which means no. In addition, you can’t trust all of the aliens to give truthful answers. Sounds impossible, right?!

Did you try your hand at solving the puzzle? Do you think you got the right answer? Let us know on our Facebook page!

How to solve it

As laid out in the video above, the key to solving this puzzle is to create a ‘hypothetical condition’ in each question, and to include either ‘ozo’ or ‘ulu’ in your prompt. The best questions to ask the aliens are defined by ‘logical structure’. As the video explains, ‘a double positive and a double negative both result in a positive.’

Watch the video above for the full explanation.