AMC Australia vs AMC 8, 10 and 12: which contest is which?
The Australian Mathematics Competition (AMT AMC) is not the US AMC 8 / 10 / 12 series. Match timed practice to the contest your school actually enters.
AMC is an overloaded name. On RubricMark, AMC means the Australian Mathematics Competition run with the Australian Maths Trust (AMT). That is a different contest from the US Mathematical Association of America AMC 8, AMC 10 and AMC 12 papers.
Australian AMC
School-entered secondary divisions (Junior, Intermediate, Senior) with a long contest clock — typically about 30 questions in 75 minutes, no calculator. Certificates use AMT norms for that year. Confirm registration with your school and amt.edu.au.
US AMC 8 / 10 / 12
Those papers are organised in the United States (and some international centres) under a different body and a different calendar. Format, scoring and invitations (AIME, and so on) do not transfer to an Australian AMC sitting.
How to choose practice
Read the school letter. If it names Australian Maths Trust or AMC Junior / Intermediate / Senior, sit that 75-minute-style paper. If it names AMC 8, 10 or 12, use US contest materials instead — do not mix clocks in the final fortnight.