Valuation of units in ipcc exams

Hi.. Please help me regarding IPCC exam units valuation. i completed my first group in PCC ( Accounts, Audit, Law), and then i converted to ipcc .. now i have to write exams units wise i.e costing, tax, it & Sm . Institute has given a options 1. to write all 3 papers ( Costing,Tax, and IT & SM ) as single unit (Unit 8) OR Unit 4 (Only Costing,Tax) as 1 unit, and Unit 6 (Only IT & SM) as 1 unit. My doubt was if i choose to write my exams as unit 6 and 4 , what will be my aggregate % to qualify in both units. in unit 8 it is 50 % overall in all 3 subjects. but how they will give aggregate to it & sm in unit 6 ? what is the pass mark for that subject ? i contacted icai help line and they are not responding well and one guy said me for costing and tax it is 50 % but for it and sm 40 marks are enough to qualify.. is it true?? please let me know as soon as possible.. Thank u..