Skip to main content

Can you solve the dark coin riddle? - Lisa Winer

4,276,572 Views

5,558 Questions Answered

TEDEd Animation

Let’s Begin…

As a world-renowned treasure hunter, you have been searching for the legendary dungeon containing the stash of ancient Stygian coins. The wizard who owns the castle has even allowed you to have them, on one condition…you must solve his seemingly impossible puzzle.

Suppose that in the dark, you pick a pile of 20 coins (call it pile A) and 8 of them are facing silver side up. How many silver-facing coins would remain in the other pile (call it pile B)?

About TED-Ed Animations

TED-Ed Animations feature the words and ideas of educators brought to life by professional animators. Are you an educator or animator interested in creating a TED-Ed Animation? Nominate yourself here »

Meet The Creators

  • Educator Lisa Winer
  • Director Outis
  • Script Editor Alex Gendler
  • Collaborator Katherine Gull
  • Associate Producer Elizabeth Cox, Jessica Ruby
  • Content Producer Gerta Xhelo
  • Editorial Producer Alex Rosenthal
  • Narrator Addison Anderson

More from Math In Real Life