A school  keeps details about students and the various subjects the student studied. Each subject is thought by one teacher. The data kept in a book with following information.
Your task is to design a database system to keep data>

The details comprise of
stNo - registration number
name - student name
address - student address
teacher - Teacher Name
tNO - Teacher number
subno - subject number
subject  - subject
marks - subject marks

Reduce the relation DETAILS to third normal form.
Do you think that the DBMS can be improves by introducing student grade?
Modify your Database with Teachers, Subjects, Grades, Students, Marks ?
What if you need to keep data by Years and terms?

STUDENTS TABLE
stNo - registration number
name - student name
address - student address

TEACHER TABLE
tNo - Teacher number
teacher - Teacher Namesubject  - subject
subNo - subject number
subject 
MARKS TABLE
stNo
subNo
tNo
marks

This is the simplest Database design.
How ever in practice we need to enter
teachers and subjects thought
students and subjects studied
before data entry into marks table therefore
more tables needed

TEACHER_SUBJECT
tNo
subNo

STUDENT_SUBJECT
stNo
subNo