You might be right ... but it's entirely dependent upon what the author meant. The problem statement was "How Many Total Hosts Were Seen as “Up” in the Past 3

You might be right ... but it's entirely dependent upon what the author meant. The problem statement was "How Many Total Hosts Were Seen as “Up” in the Past 3 Months" which I read as "How Many Total Hosts Were Seen as “Up” in any of the Past 3 Months". You've correctly pointed out that the author might have meant "How Many Total Hosts Were Seen as “Up” in all of the Past 3 Months". This sort of ambiguity is why BDUF is so hard to pull off. Only lawyers are trained to write completely unambiguous prose (and they fall back to having very precise meanings for words to help them succeed).