Hi

You have tagged PUC   karnataka board.

In karnataka board, the passing marks is 35 % in each subject.

So, if your subject is of 100 marks then to pass that subject you need at least 35 marks.
It means with 31 marks, you will fail in your examination.

For details checkout:-
https://school.careers360.com/boards/dpue-karnataka/karnataka-puc-syllabus

Follow the given below tips to score well in your board examination :-

---------) Go well through your textbooks

---------) While reading the book, underline the important points and then later make short notes

---------) Do go through the questions at the end of the chapter, just reading is not going to help.

---------) Follow a routine, it should be such that it moves around 3 important things i. e first studying, then practicing questions and finally revision.

---------) Focus relatively more on your weak subject so that you can make them strong

---------) Have daily, weekly and monthly goals like you will complete these topics today , these chapter by the end of the week and these many chapters by the end of the month

---------) Be practical in your approach. For example, if you need 4 days to complete a chapter but you plan to finish it in 1 day from scratch then that's not going to help you, at  the end of the day it will give you disappointment and down your morale, so be practical.

---------) Complete your syllabus at least 1 month before your board examination so that you can give it for revision and practicing questions

---------) solve previous year question papers :- it will be really of great help to you because you will know what type of questions are asked in the exam, their difficulty level , examination pattern etc

---------) Go through chapterwise and unitwise test and once you're done with the complete syllabus ,go through full mock test papers. And do at least 5-10 full mock test papers in each subject.

---------) practicing days full mock test papers will let you know the level of your preparation for your board examination .

---------) after each mock test analyse your performance to know your mistakes / weak areas , after that you need to work on improving them in the subsequent mock tests .

I hope that you find this helpful.

Thank you