TED-Ed
Can you solve the fantasy election riddle? | Dennis E. Shasha
After much debate, the realm has decided dragon jousting may not be the best way to choose its leaders, and has begun transitioning to democracy. Your company was hired to survey the citizens of the land and predict which candidate will...
TED-Ed
TED-Ed: Can you solve the riddle and escape Hades? | Dan Finkel
The underworld is overcrowded, and Zeus has ordered Hades to let some spirits out. Hades arranges all the souls of the dead in a line before Cerberus. When one of his three heads bites down on the soul in front of it, they'll get...
Curated Video
Maths Puzzles Part One
This video contains four maths puzzles with answers. These maths puzzles are great for brain training and for lesson starters. Pause the video while you work each one out.
Curated Video
Problem Solving Puzzles
This video contains four maths puzzles with answers. These maths puzzles are great for brain training and math lesson starters.
Khan Academy
Khan Academy: Brain Teasers: Liar Truthteller Brain Teaser
Video explains how to solve a brain teaser involving two doors, with treasure behind one of the doors. Two people guard the doors. The first is honest and always tells the truth. The second lies and never tells the truth. What question,...
Khan Academy
Khan Academy: Brain Teasers: Forehead Numbers Brain Teaser
Video sets up and solves the following brain teaser: Three people with infallible logic are in a room together. Each has a number painted on their forehead. The numbers are unique, greater than zero, and one number is the sum of the...
Khan Academy
Khan Academy: Brain Teasers: Alien Abduction Brain Teaser
Video explains how to solve a brain teaser involving ten people who have been abducted by aliens. The people are arranged single-file, facing the same direction. Each person is wearing either a purple or green hat. No one can see the...
Khan Academy
Khan Academy: Brain Teasers: Toggler Brain Teaser
Video explaining how to solve a brain teaser involving five people. Four of the people are togglers--they alternate between lying and telling the truth--and the fifth person always tells the truth. The goal of the teaser is to figure out...
Khan Academy
Khan Academy: Brain Teasers: Blue Forehead Room
Video explains the following brain teaser: One-hundred perfect logicians are blindfolded and each has their forehead painted blue. They all enter a room with the lights off, sit in a circle, and the lights are turned on. Each logician...
Khan Academy
Khan Academy: Brain Teasers: Light Bulb Switching Brain Teaser
Video explains how to solve the following brain teaser: One hundred light bulbs are arranged in a row. Each light bulb can be either on or off. On the first pass of the row, each bulb is switched on. On the second pass, every other bulb...
Khan Academy
Khan Academy: Brain Teasers: 3 D Path Counting Brain Teaser
Video explains how to solve the following brain teaser: Starting in the upper left rear block of a 3x3 cube, how many different ways are there to get to the bottom right front block of the cube, with movement restricted to moving to the...
Khan Academy
Khan Academy: Brain Teasers: Blue Forehead Room Solution
Video explains the solution to the following brain teaser: One-hundred perfect logicians are blindfolded and each has their forehead painted blue. They all enter a room with the lights off, sit in a circle, and the lights are turned on....
Khan Academy
Khan Academy: Brain Teasers: Path Counting Brain Teaser
Video explains how to solve the following brain teaser: Starting in the upper left hand corner of a 6x6 grid, how many different ways are there to get to the bottom right corner of the grid, with movement restricted to moving to the...
Khan Academy
Khan Academy: Brain Teasers: Alien Abduction Brain Teaser
Saving Earth from becoming a mushroom farm.