System Analysis and Design - Old Questions

2.  "Students participate in exams for five courses each having 100 marks. To pass the examination students should obtain 50% marks in each subject. If the students obtain 80% or more marks of the total marks, he/she will get distinction, if 70% or more, first division, if 60% or more, second division, otherwise third division". Draw ER diagram and data flow diagram for a result processing system described in the above narrative.