Central Board Of Secondary Education [CBSE] — different difficulty level of sets, class x

I am a student of class x and so far 3 of my exams are over, one thing that i have noticed is that, there were different questions in each paper which were of different levela of difficulty, i had set 2 for science, which was the hardest among the 3 sets, i had prepared very well for this exam and i lost marks simply because i got the hardest set and because luck wasnt with me, some queations were even out of syllabus, i came out of the exam hall in tears meanwhile on the other hand, my friend who didnt put much effort into studying this subject, got the easier set and she came out smiling because it was easy for her. It is highly disappointing to see that cbse is conducting exams in this manner, i request liberal cheking for all of the harder sets in all subjects, this is a matter of injustice and inequality, hopefully this matter will be taken into consideration.