Three papers, three completely different ways to lose marks.

The one leaking the most marks, which is rarely the one that feels hardest. Split a recent mock by subject and compare marks solved against marks scored — the paper with the widest gap is where an hour of work pays back most, whatever your instinct says.

It is usually the longest, not the hardest. Maths punishes time management and single-line arithmetic slips more than the other two, so students lose marks there on questions they could solve — which reads as difficulty but is actually accuracy and pacing.

Less than most students assume. Physical Chemistry is almost entirely method, Organic is mechanism and pattern rather than a list, and only Inorganic rewards recall. Students who treat all three as memorisation lose Physical and Organic marks they had the method for.

Both, in that order. Chapter-wise work fixes the concept; full mocks are the only thing that tests it under time pressure and negative marking, which is where most of the loss actually happens. Mocks without chapter work just re-measure the same gap every week.