question for the guards

You know how there's that thing of the two guards, one always tells the truth and one always lies, and you have to figure out who is who? What if you just ask like, what is 2+2? Like does that work, or would they just be upset with me cause that isn't in the spirit of the puzzle? Or is it a situation where I am compelled to ask a more useful question because I need the answer to progress, like asking if the next area is safe? I just don't wanna rain on their parade, but if I can min-max my one question I'm speedrunning the guards cause they have to be guarding something more interesting than them.