Puzzle - 2

Last time I had sent the following puzzle that was sent to me by Tanmay, son of a good friend of mine.

There are 250 statements, each of which is either definitely true or definitely false. Statement number 'n' says that 'n' statements, out of these 250, are false. For example, statement number 50 states that 50 statements are false. The question is, how many of these 250 statements are true?
We disagree on its answer. Tanmay thinks that first 125 statements are true. I think only one namely 249th is true. His reasons are as follows,
Let us take the 250th statement first. Obviously, it cannot be true, as that would make all statements, including that one, false. Now for the 249th statement. Again, if it is true, then all statements preceding this statement are also true. Remember, the nth statement says atleast n statements are wrong, so that atmost 250-n statements are right. If n = 249, atmost 1 statements is right, but our assumption that atleast 249 are wrong means that the statement that atleast 1 statement is wrong is also true. Thus, 1st statement is true; likewise, all the first 249 statements are true. As such, one can proceed like this for each of the statements. Finally, the 125th statement will not be a paradox. It will be noticed that this paradox will exist even for the first 124 statements. Thus, 125 statements are correct.
I think only one namely 249th statement is true. My reasons are as follows
250th statement cannot be decided, as it becomes a paradox if you apply to it. If 249th statement is true then this makes other statement to be false. This is consistent with the other statements. Let’s take 1st statement that says that only one statement is false. It is false as 249 statements are false. Similarly 250th statement is false as it says 250 statements are false but only 249 are false.
Difference lies in assuming whether nth statement says that 'atleast' or 'only' n statements are false. In fact puzzle does not use either of the words. Tanmay thought that it gives impression of atleast whereas I thought that it gives impression of only. I never thought that interpretation of puzzle was so important. I will wait for your comments.
Here is another one
There is a virus. It multiplies to seven in an hour. There is one virus in a bottle. It takes 50 hours to fill up the bottle. How much time was taken to fill up the 1/7 (one-seventh) of the bottle? How much would it take to fill up 1/7 of the bottle if to begin with there were 7 viruses.