Theory questions in practical subjects

Hello CCI members,

I have some questions regarding preparation for theory questions in practical subjects(IPCC) :

COST and FM:-

In costing and fm around 32 marks are allotted to direct theory questions.

       So,is it sufficient to score maximum marks in theory if we read from Institute's Practice Manual or is it necessary to read from Institute's study material or from any standard reference book or from a combination of these?

INCOME TAX:-

Around 12 marks come from theory area,if I am not incorrect.

       So it necessary to read the entire theory part of income tax or is there any other approach? Please suggest on how to score well in income tax theory.

ACCOUNTING(GROUP 1 and GROUP 2):-

Here again 5 to 10 marks in each group(i.e.10 to 20 marks in both the groups put together) would be from theory area.

       Most of the theory in company accounts chapters is covered in company law.So,what are the remaining areas from where theory should be studied apart from Accounting in computerized environment which is an outright theory chapter.And is it enough to cover theory in institute's practice manual or from any other source(i.e,study material,reference books,etc)?

All the above questions are for scoring high marks in theory area and not for scraping through the theory area.