Well the short answer is ... all of them!
Financial Maths
Preliminary Course: FM1-3
HSC Course: FM4-6
Data Analysis
Preliminary Course: DA1-4
HSC Course: DA5-7
Measurement
Preliminary Course: M1-M4
HSC Course: M5-7
Probability
Preliminary Course: PB1-2
HSC Course: PB3-4
Algebraic Modelling
Preliminary Course: AM1-2
HSC Course: AM3-4
Check the HSC-on-line site for more info about each of these topics.
http://hsc.csu.edu.au/maths/#118037
Remember that a maximum of 30% of Preliminary Course material can be used in the final exam, so that means most of next week's paper will be from the HSC Course topics.