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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: Forehead Numbers Brain Teaser
The perfect logicians are at it again.
Khan Academy
Khan Academy: Brain Teasers: Toggler Brain Teaser
Separating the truthteller from the togglers!
Khan Academy
Khan Academy: Brain Teasers: Blue Forehead Room Brain Teaser
What happens when 100 perfect logicians have to figure out if they each have a blue forehead?
Khan Academy
Khan Academy: Brain Teasers: Light Bulb Switching Brain Teaser
Turning light bulbs on and off.
Khan Academy
Khan Academy: Brain Teasers: Alien Abduction Brain Teaser
Saving Earth from becoming a mushroom farm.