View full lesson: <a href="http://ed.ted.com/lessons/can-you-solve-the-counterfeit-coin-riddle-jennifer-lu" target="_blank" rel="nofollow">http://ed.ted.com/lessons/can-you-solve-the-counterfeit-coin-riddle-jennifer-lu</a><br /><br />You’re the realm’s greatest mathematician, but ever since you criticized the Emperor’s tax laws, you’ve been locked in the dungeon. Luckily for you, one of the Emperor’s governors has been convicted of paying his taxes with a counterfeit coin, which has made its way into the treasury. Can you earn your freedom by finding the fake? Jennifer Lu shows how.<br /><br />Lesson by Jennifer Lu, animation by Artrake Studio.