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Mess of 100 Bucks: Calculating the Loss
In this video, the teacher describes a scenario where John sells a cap for $50 with no profit or loss. However, a buyer comes with $100 and John has to give change. After some complications, the teacher poses the question of how much...
Let's Tute
The 19 Camels: A Math Puzzle with a Clever Solution
This video tells a story about how an old man's will to distribute 19 camels among his three sons seemed impossible until a villager came up with a clever solution. The video also explains the mathematics behind the solution and...
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...