Hello!

By practicing past 10 years papers you can score above 45 marks. It will almost cover the entire  topics but to score that 25 marks you should study the book at least the glimpse of certain things. Even there are good chances to get more than that. Not just theory and derivation is not enough you should also practice the sums from the past 10 years.

ALL THE BEST. Hope the answer was helpful.

thank You