UPSC is one of the toughest exams in India. While several thousands of users appear for the examination, only a few hundreds of them get postings. So, to crack the examination, many people recommend studying almost 15 to 16 hours a day. In reality, it is not the number of hours that you study that matters, but the quality of study. There is no ideal answer to this widely asked question as it depends on the candidates grasping ability and attention to studies. Also, you need to be motivated all throughout the preparation phase to crack the paper.