Table: Detail AS T1

ID Activity Amount
a open 15,000
a reviewed 15,000
a closed 15,000
b open 20,000
b reviewed1 20,000
b reviewed2 20,000


c open 35,000

Results desired: A query that passes only 1 record for each activity set where the set of like IDs doesn't contained an activity "Closed".

Resulting record set
ID Activity Amount
b open 20,000
c open 35,000

I know there's something about comparing the table to itself (T1 and T2) and using an exists statement. Just can't figure out how to do it.

Thanks in advance,
Mark