You get your entry score generated by your LALS B mark and your 2 best other B module scores.
So really you only have to do 3 A modules and 3 B Modules.
I am doing the TPC at Ultimo and this is the drill:
Classes are in 2hr blocks.
Physics, Chemistry & Biology are 6 hrs a week
LALS is 4
Prelim Maths, Foundation Maths, Adv Maths, Calculus & Statistics are 4 hrs (I am 99% sure anyway)
Dunno about Humanities though I would assume 4
Unless you do evening courses, then it's 1 4hr class a week for all science and LALS. Obviously no night classes for the minor subjects.
Also, all science B modules are only offered in the second semester.
But you should check with the TPC co-coordinator at your desired institution