Eeeek! I was still wrong! How about 20m apart. I forgot the cable had to come back up. 80-20=60, so hangs down 30m on the 50m pole, 20m above the ground. Why I never post anything!

So I'm a retired software engineer with many years experience. And I don't know that this is a bad or unfair interview question. Throwing the interviewee a little off guard is an excellent way to get a sense of their problem-solving approach. Will they tackle it or fold? Will it bug them incessantly until they solve it? Do they get defensive or combative? These kinds of data points tell me a lot about what they are made of, and how they will be to work with. And that is every bit as important as any other consideration! How smart they are and their mathematical prowess are really secondary considerations, in that those issues will apply to only a tiny subset of the interviewee population. Most of the projects I've worked on, I'd much prefer a hard-working, practical, easy-to-get-along-with co-worker to a genius snowflake. And a solver to a disrupter. As to part B, you don't need catenary, because the shape of the cable is NOT a part of the problem. And since we are given the 10 foot value in part B, we can assume the person asking it presumes a theoretical solution, because that's the only approach that will result in that answer (any real-world factors like "bend radius" will result in a greater height). 1) conservation of cable - the answer will depend on the cable length staying 80 meters. 2) (okay catenary - it is a function) there will be a single Y value for each x value. So if the cable hangs 20m from the ground, then 30m of it are used up by Y values. (50-20) So there is only 50m (80m-30m) of cable left for x values, i.e., the poles are 50m apart. Answers are a) 50m and b) 0m. (60m is wrong, because the cable could only hang down 20m, or 30m from the ground)

Are we talking about IP rights again? Sounds like the MAFIAA to me.

Cool! But parallel viewing works just fine, too. How 'bout a version in that?

I develop software in a medical device environment, so we're ISO 9001 certified, follow FDA good manufacturing practices, our own quality system, etc. The only reason it all hangs together is there are people whose job is Quality Assurance. People who audit everything, and if we don't follow what we're supposed to then we get dinged: have to go to remedial training, have to sit through even more meetings discussing why we screwed up, and have to revise the procedures yourself if they aren't right. So the path of least resistance is to document, do it the way its documented, and pass the audits. This takes massive management commitment to keep in motion. We joke it's the CJO's(chief jailable officer)problem, but they don't think it's that funny. It's part of the bottom line. So in your case, unless you have commitment, enforcement, and punishment it just ain't gonna happen. I was in a company once that went for ISO certification from scratch. It took over a year to get there, a great and dogged commitment on the part of management, and a good chunk of resources to implement. Of course, it was for a government contract. What system is the best, how to capture knowledge, etc. are all sorted out in the planning meetings after the commitment is made.