So far I've received 11 emails, but 4 were some variant of "nice puzzle, happy where I am right now, but I'll write to you next time I'm looking for work."

A few more were "I solved the puzzle, but tell me more before I bother to update my resume." Such people are certainly in the right ballpark - if you jump into a puzzle without even thinking about whether you want the prize, that's a win.

Thanks. I wondered if the puzzle might encourage more responses in addition to filtering out the send-a-resume-to-everything ones. The puzzle differentiates you from most of the open positions.

It definitely did. I'm working on a blog post discussing this.

Are you replying to people? I sent in the answer on Friday but I haven't heard anything back. Now I'm worried I messed up somewhere. I don't see how though, all the math works out.