Please help ..on basic sql query. .. : I have three tables ..  
Student 
I'd.    Name 
1      vesd
2.     Eet

Subject table 
I'd  name 
1.   Science 
2    maths 

Marks 
Stud_id.  Sub_id.  Marks 
1.             1.           20
1.             2.           30
2.            1.            40
2.            2.           50 