It was and is supposed to be solvable from first principles. It wasn’t a “gotcha” or “stump the idiot” question. Like any question, it would be easier if you kn

It was and is supposed to be solvable from first principles. It wasn’t a “gotcha” or “stump the idiot” question. Like any question, it would be easier if you know it first. The point of the post is that things that people know may be hard to remember during the interview and to give them more time than you would need for the same question yourself.