How to score 80+ within 15 days

Which chapters should I study? Should I just focus onlyon chemistry and try to attend 20 questions with justchemistry or should I study physics and chemistry. I just need 80 marks. I know most of Physical chemistry and organic chemistry i studied but haven't practiced. And in physics I just know 30% of all chapters, like I haven't finished any chapters completely So for 80 marks , in these last 15 days what chapters should I study. I just need to make sure I Get these 80 marks no matter what Please UPVOTE. So someone can help Please help