One member=Chapter?
 

How can you have a chapter with one member?

Background:
I am on a campus expansion committee as an alumna representative. The student representative for the fraternities was giving an overview and mentioned chapters range in size form 1-85.

Simple explanation is that the chapter used to have more members. Through graduation, transfers, resignations, etc, there is only 1 active member remaining at this time.

This is most likely a D9 or NMGC org, which tend to be unconcerned with size, in contrast to NPC/IFC groups.

^^ Or city-wide

Can you elaborate on this? You mean it's a city-wide chapter, so the individual school reports it as one member, but he's really in a chapter with thirty other guys from a different school?

Incidentally, many schools of which I have close knowledge require at least 3 people to be a student org.

^^ Pretty much

All of the above.