TED-ED: Can you solve the counterfeit coin riddle? - Jennifer Lu

The video tutorial presents a problem where the viewer, as the kingdom's greatest mathematician, must identify a counterfeit coin among twelve using a balance scale and only three weighings. The tutorial explains a strategic approach to solve the problem by dividing the coins into piles, using a marker to track results, and employing logical reasoning to narrow down the possibilities. The process involves initial and advanced weighing techniques to determine the fake coin, which is either slightly heavier or lighter than the others. Successfully identifying the counterfeit coin earns the mathematician freedom from the dungeon.

What opportunity is given to the mathematician to earn their freedom?

How many times can the scale be used to identify the counterfeit coin?

Describe the first step in identifying the counterfeit coin among the twelve coins.

What should be marked on the coins after the first weighing if they balance?

Explain the strategy to follow if the two sides of the scale do not balance.