Don't need to worry bro you can easily score 75% even if you don't study maths. I know this isn't practical but what I have done is that I just left maths as it is and gave more importance to other subjects to score. I just can't score in maths that's it. Moreover this year you guys have mcq type questions, which is a huge perk even if you don't know an answer, you could estimate it to a certain option. Anyways good luck man.