Hey! I graduated high school this year and was a du student (A2 yr 11, A3 yr 12) and I want to say that du isnt the type of thing for everyone. For me, it magically helped me from failing a year 11 3u test to almost getting full marks in the hsc, yes, it is really useful if you are 'mathematically talented' and willing to put in hours of hard work doing their hw, however I kind of ignored my schools math work (we used mif) and teachers will hate you for it. Thing to say is tho, if you cant get into the As, there really is no point going. Try your best in the entrance test note i got 67 and was placed A2, i heard roughly 40-50 is A3 so good luck