Skip to main content

Can you solve the seven planets riddle? - Edwin F. Meyer

4,349,690 Views

5,872 Questions Answered

TEDEd Animation

Let’s Begin…

Your interstellar police squad has tracked a group of criminals to a cluster of seven planets. Now you must apprehend them before their reinforcements arrive. Of course, the fugitives won’t just stay put – they’ll try to dodge you by moving from planet to planet. Can you devise a sequence for searching the planets that’s guaranteed to catch them in ten warps or less? Edwin F. Meyer shows how.

Additional Resources for you to Explore

The strategy of simplification allows problem-solvers to gain new insights about possible solutions that may be difficult to grasp when looking at too many variables. This is clear in the TED-Ed lesson Can you solve the famously difficult green-eyed logic puzzle? – Alex Gendler.

It is difficult to see how anyone could make progress on this problem without reducing the number of prisoners from 100 to two. With only two prisoners, it is not difficult to understand that the statement, “There is at least one green-eyed person here,” gives Adria new information because she now knows that Bill knows there is at least one green-eyed prisoner.

When a problem seems too challenging and you have no idea have to make any progress on it, simplification usually provides key insights into the solution. To learn more about the importance of simplification, check out this site. To explore more math equations, click here.

Next Section »

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 Edwin F. Meyer
  • Director Franz Palomares
  • Script Editor Alex Gendler
  • Lead Designer Barbara Bakos
  • Riddle designer Tara Sunil Thomas
  • Composer Cem Misirlioglu
  • Sound Designer Cem Misirlioglu
  • Associate Producer Elizabeth Cox, Jessica Ruby
  • Content Producer Gerta Xhelo
  • Editorial Producer Alex Rosenthal
  • Narrator Addison Anderson

More from Math In Real Life