Hello, nice to meet you.
you mean numerically, or do you mean if he answered correctly, we could think he knew really ? (1 seems here a bit naive/gentle seen the other data), except if we define "correctly" as neither copied nor guessed.
(the probability it was just guessed, (maybe it can be discussed on the meaning of this word, either : taken as : put at random, like after dice throwing, the correct one, without knowing, or with some intuition/instinct evident from itself, which would then be taken as equivalent to "knowing"), is 1/3, dumbly copied (hence without knowing), 1/6*1/8, which leaves
31/48 at most, among them, without random nor copying some people answered not correctly)
remain the data : 4 which was not used.