studytonight

UNF:
Student:
S_id S_Name S_Address Subject_opted
401  Adam   Noida     Bio
402  Alex   Panipat   Maths
403  Stuart Jammu     Maths
401  Adam   Noida     Physics

UNF
Student:
Student Age Subject
Adam    15  Biology, Maths
Alex    14  Maths
Stuart  17  Maths

1NF:

Student:
Student Age Subject
Adam    15  Biology
Alex    14  Maths
Stuart  17  Maths
Adam    15  Maths

2NF:

Student:
Student Age
Adam    15
Alex    14
Stuart  17
Adam    15

Subject:
Student Subject
Adam    Biology
Adam    Maths
Alex    Maths
Stuart  Maths

3NF:
Student         (Student_id*, S_Name, S_Address)
Student_Subject (Student_id*@  Subject_id*@)
Subject         (Subject_id* Subject_name)