Light Bulbs Go On (and Off)

Here is the latest problem that Mustard Seed School students in Grades 6 - 8 are working on.  We hope you enjoy it.  Please feel free to send solutions, questions and comments to Mr. Lawrence at glawrence@mustardseedschool.org.

Be sure to look at the next post to see who our visiting mathematicians will be on I Love Math Day.

Enjoy!

This problem comes from More Thought Provokers by Doug Rohrer and Joe Spooner, 1994, Key Curriculum Press.