Help for costing paper - urgent

Dear Friends,

As I am going to sit for 2nd group on 13th Nov 2013, but as yet could not get the confidence in Costing Paper. Will you please help me in understanding the main topics which must be done so that I can get the marks between 40-50 because I have prepared rest of the papers good.

Please let me know the main topics which must be covered to get the marks between 40-50. Please help me

Regards

Deepak Arora