brs2585,
I went on the nupoc interview back in october, its only stressful if you let the people around you get to you...there were atleast 20 people in my group and only one guy got asked back up stairs for a 3rd question, the rest of us only got two questions. the 3 question guy was a current enlisted sailor going for instructor, so i don't know if that had anything to do with it...
that interview book is pretty good in terms of giving you the right types of problems to work (id work all the ones in your major area and all the math), but the thing it doesn't stress enough is that it is an interview and no so much a test. sure you have to answer questions, but it's important to talk to the interviewer like you know what's going on...talk about past experiences in some lab, think about problems you had with a particular lab and how you went about solving those problems (typical interview questions that all other major corporations would ask)
I got my degree in physics and was asked two questions by the first guy and 1 question by the second guy...and the second guy took a little linger than the first. I finished his problem in about a minute and then we just talked for like 20 minutes about what i'd been doing in my job (i already graduated at the time) and then i asked him questions...(you might want to think of some questions that you'd really like to know and not something that can easily be found in a google search)
I'm going to be an instructor...someday...my training date keeps getting pushed back, it was january...now its august...but that's how it goes...