How to solve previous years board papers? I started physics and maths earlier. How to complete then before boards? Please help me because even after efforts which I put in I am unable to secure above 50 out of 70.

First go through your textbooks thoroughly. If you are confident that you can solve sample papers perfectly then you Should try them on and I'm sure you'll score well on your own testing and in boards exams as well.

I hope it may be helpful to you!
Thankyou!