# Some Good News! “Combinations” is NOT on the LC Ordinary Syllabus.

Some of the books for LCO include a section on Combinations / Selections as well as Arrangements / Permutations.

However, we work directly from the official syllabus and we can see clearly (at the top of page 17) that Combinations / Selections is NOT required for LCO (only for LC Higher).

Just to make sure, we contacted the NCCA who are responsible for the curriculum, and they confirmed our understanding as above. You can read an extract from their email below if you wish.

So, in summary, **there is no need to cover this Combinations / Selections material for LCO** which is good news, as it is one less thing to study!

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“The syllabus does not use the terms permutations / combinations. This was deliberate so that students would get a clearer understanding of what is involved (arranging / selecting respectively).

The syllabus is quite clear: OL students (and therefore also HL students) are expected to be able to count the __arrangements__ of n distinct object (n!) and also the number of ways of__arranging__ r objects from n distinct objects.

__
In addition__, HL students are expected to be able to count the number of ways of

__selecting__r objects from n distinct objects.”