Central Board Of Secondary Education [CBSE] — Partiality and favouritism

Hey you announced that the ratio of class 10th, 11th and 12th marks is 30:30:40 for calculating the correct marks but here in my school in Kerala named St.Marys Cathedral Public School calculated in the ratio 15:10:4 for my mathematics paper and i got 28 for theory and 20 for practical.So total 48 marks for mathematics.In my class my roll no is 3 and rolls numbers from 1 to 5 got the same mark in mathematics and all others got 70+ in maths.This is utter partiality from the teachers giving good marks to the ones they like.Is this how marks are calculated huh?In Kerala there is an exam called KEAM in which one should attain 50 mark in maths i only have 48 due to incorrect evaluation.What should I do if these teachers are not doing correct evaluation and the students like me are not getting the deserving marks.U guys must strictly warn these teachers in my school.