Hours To Study

This is the toughest question to answer and I think there cannot be direct answer to this question. It varies for individual to individual and from time to time. But for sure following rules apply

1 - Regular studies gives better results

2 - Follow a time table

3 - Have good gaps in between for recreation/sports

4 - Try puzzles, quizzes to sharpen your brain

5 - Test your self regularly to see where you stand and plan accordingly.