Is it possible to learn a language in 3 or 4 months?

People have been asking me about the real possibility to learn a language in a short period of time like 4 or even 3 months, but to give you the right and precise answer I will invite you to think carefully, and I will ask you another question, would you believe me if I said I studied a language and learnt it in 7 years? Probably you will believe, won't you?
So If you apply to a language course in a private school, how long will it take? According to their promises from 5 to 7 years, so let's take the average number of 6 years, people usually attend to such courses one hour (or 50 minutes) twice a week, 10 or 11 months a year, so the number of hours studied in language schools is about 480 hours.
So, it is mathematical accepted that with 480 hours a person can master a language, and with this in mind we can continue with the question titled in this post: is it possible to learn a language in 3 or 4 months?
Obviously not, if you study it only one hour twice a week, but absolutely yes, if you dedicate at least 5 to 6 hours daily to this. As you can really see, if you are really determined to learn a language and have time to do this it is totally possible learn it in 3 months, for this reason you should not be impressed if a polyglot claim that he can learn a language in this short time, providing he is immersing himself in the process.
The next question should be, is it easy? Well, to answer this question I will need other post, so soon I will speak about the easiness or difficulty about it.