"Find the probability that the fourth Q Bob attempts is the 2nd that he answers correctly."lol shuniing, what a way to "invade" my account and use it for your advantage xD.
From my point of view, we shouldn't assume that the 4th attempt means winning. It can be either winning or losing...well that's from my own interpretation.
From this wording, I think it actually does imply that the 4th attempt must mean winning.
Although what is the exact wording of the question?
I do agree however that probability questions are sometimes ambiguous