between the lines

In games of probability, the rules dictated that in any situation where choice was given, no matter how uncertain, there was always the possibility of arriving to the right conclusion—even if it was just by chance.In other words, in a game of probability, the only way to get all the wrong answers was to know all the right ones.This was why Severus was still under the impression that this was all some kind of joke.In an exam—in this exam—where the paper given had been structured as multiple-choice of 100 questions, with four answer options given per question, where the probability of guessing the correct answer, even by chance, was 25%, Bruce Mulciber Jr. had gotten every single question on his Herbology preNEWT exams wrong.