You have only 3 questions. If you formulate a hypothesis like "A is True, B is False and C is Random", with a naive approach you will waste much more than 3 questions just to test this single hypothesis (and statistically, it will be false, so you will need to test more).
I think there's also the implied "or they will kill you" to encourage a non-brute-force method. While this one in particular doesn't mention any death threats, most problems of this kind do. I mean, why else limit yourself to their constraints, if not to preserve life / sanity / coffee / beer?
except that you aren't limited to falsifying a single premise with each question. remember guess who? the first thing you learned was to eliminate as much of the search space as possible with each step.
i'd say the average code base works your brain harder.