Behrend's ~ "One to Think About"

Every so often we will be posting questions, (both on this site and throughout campus), that are designed to keep us "on our toes". During the year, ACM holds contests in which members of ACM can sign up for and compete in. Here is one you can start with for now. We will continue to post new questions, and we encourage you to submit your own to the webmaster.


Question 1:

A computer cable has seven connectors, arranged in a perfect circle -- so by rotating the plug, it can be connected to the outlet in any of seven different ways. Each of the connectors is numbered from one to seven, each number being used exactly once. The same is true for the holes in the outlet. The device that uses this cable only requires that one of the connectors match up to its corresponding hole in order to operate. How should you number the connectors on the plug and the holes in the outlet so that, no matter how the cable is rotated and plugged in, at least one connector matches up?

 

Answer is at the bottom of this page! (Don't Cheat!)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Answer

Number the connectors clockwise, with consecutive numbers: 1, 2, 3, 4, 5, 6, 7. Number the holes clockwise, with every other number, then wrapping back around: 1, 3, 5, 7, 2, 4, 6.


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