PERSON(NID , NAME) ATTRIBUTES OF PERSON ENTITY
QUALIFICATION(NID , EXAMID , QUALIFICATION) SINCE RELATION CONTAINS KEY ATTRIBUTES OF BOTH ENTITIES ALONG WITH ITS ATTRIBUTE
EXAM(EXAMIID , EXAMNAME) ATTRIBUTES OF EXAM ENTITY
SINCE EXAM IS NOT WEAK ENTITY
EXAM(EXAMIID ,NID, EXAMNAME) COULD NOT BE HOLD