Yeah, but they are really important to know for interviews. Which of course may or may not have anything to do with the actual life of a developer, but that's life.
The interview was 99% math. The people who asked me question looked all smart alecs and their questions all seemed to indicate that they wanted to show me how intelligent they are, and how stupid I am.
By the end of the interview it was clear to me why they were stuck. Those people had absolutely no interest in building things. It was all about individual One-upmanship, and showing their little math and puzzle tricks they would have gathered by combined reading on the internet over the years.