I found it. . ."And Then There Was One" by Ross Rocklynne.  The way I found it was interesting: After I posted my question, I started looking through other's questions to see if I could help out.  I came across a question about two men who get stuck on a frictionless mirror surface.  I thought. . .wow, that sounds like one of the stories in the anthology that my story came from.  So I looked at the answer and it said the story was "The Men on the Mirror" by Ross Rocklynne and was from an anthology of the same name.  I looked up that anthology on ISFDB and found "And Then There was One"  then I had only to find a summary of ATTWO (I actually ordered the book from Amazon as well). . .and voila. . .story found!  So this website helped me find the story in an unexpected way!  Thanks everyone!