This question makes no logical sense. From Statement 1, we learn that there are some restrictions on what n can be, but we have no idea if these are the *only* restrictions on the value of n. If they are, of course you can count how many n there are. If they are not, then of course you can't without more information. There's no way to guess which case is which unless you have some psychic connection with the question writer. The format of the question is simply illogical. Where is it from?

knight247 wrote:This is from the GMAT study books of a coaching institute here in Mumbai. This particular question is listed as a 'very hard' problem.

Sure, it's 'very hard', because it's impossible to tell what it means. It's easy to invent 'very hard' problems - for example, I could ask "What prime number am I thinking of?" That's a hard problem for anyone (but me) to get right, but it's certainly not a good practice problem. The same is true of several of the questions you've posted recently on this forum, which I guess must be from the same coaching institute - they're badly written, make next to no logical sense, and often have the wrong answer. If you're preparing for the GMAT, you absolutely should find higher quality materials to study from, because you're just wasting your time with this institute's material. Even using only the questions posted to this forum by other participants you'll get much better practice than you're getting from studying questions like the one above.