Ternary Relationship cardinality

I am working on an assignment which has 2 ternary relationship. I'm can't figure out their cardinality.

Maybe I am going through one of those mental blocks...

Can someone give me some cardinality examples for N-ary relationships? all the pics i found on google images don't include this..

My other option is to convert the 3-ary relationship into a weak entity.. but I'll definitely loose marks on that

Is it ok to have N'ary Relationships which includes recursion? looks kind of odd to me
eg [person](buyer) trades [item] with [person](seller)

Thanks,

Mike Received on Mon Sep 18 2006 - 20:57:27 CEST