How many number if scientist belong to project AeH1
select count ( * ) from projects as t1 join assignedto as t2 on t1.code = t2.project where t1.code = "AeH1"
How about project Ast3, how many scientists?
select count ( * ) from projects as t1 join assignedto as t2 on t1.code = t2.project where t1.code = "Ast3"
How about project AeH3
select count ( * ) from projects as t1 join assignedto as t2 on t1.code = t2.project where t1.code = "AeH3"