Hi, I'm Anders, this is my first post here, although I have already been reading posts here for months. I've decided to finally create an account here because I really need help with the number of hours I should be studying. I've already searched and I saw many posts here about this subject, however my situation is a little bit different from these... I'm 15 years old and a freshman/sophomore, since here in Brazil we have only 3 years for High School. I plan to enter one of the best universities that we have here, it's called ITA. Entering a university here does not depend on GPA, letters and etc. We just have to do tests for each university we plan to enter. ITA's admission tests are so difficult, that students usually have to study with undergraduate-level books to have a chance. I had to explain all these things to tell my situation: I am on vacation until the end of January, and I planned to use these 2 months to study a lot (I know people will say I should rest, but I've done this during all this year). The subjects I plan to study are: Organic Chemistry, Physical Chemistry, Optics, Waves, Single Variable Calculus and revising Trigonometry. I have to study 14~15 hours each day in order to be able to finish these tasks, sleeping 8 hours per day, and eating normally (Not necessary to say things about social life, I talk to my friends every day and I don't like to go out to the movies or mall). Calculus is not required to do ITA's tests, I'm learning it because I love math. I've been using Apostol's book because from the many books I tried, this one was the only one I liked. However, it takes me at least 5 days to finish one chapter, so I wouldn't finish it when classes started again. The reason I created this post is: Is this all I'm doing correct? Should I study less? Is what I'm planning to study even possible to study during this period? I'm already tired due to this situation, I try to study, but I don't know if I'm going to finish everything, so I just keep doing nothing. And it is desmotivating me. Sorry for this long post, but I need help.