> df2 <- data.frame("StudentId" = c(1,1,1,2,2,3,3), "Subject" = c("Maths", "Maths", "English","Maths", "English", "Science", "Science"), "Score" = c(100,90,80,70, 60,20,10))
> df2
  StudentId Subject Score
1         1   Maths   100
2         1   Maths    90
3         1 English    80
4         2   Maths    70
5         2 English    60
6         3 Science    20
7         3 Science    10

StudentId Subject Score
1         1   Maths   100
3         1 English    80
4         2   Maths    70
5         2 English    60
6         3 Science    20