how can i exclude failed students in different subjects

[alizai]

Dear friends

i am working on a student result sheet, in which i have a problem i.e different subject have different passing criteria which means that on the basis of percentage like 40%, 40 out of 100 marks, 30 out of 75 marks, 20 out of 50 marks and 10 out of 25 marks.

1) how can i exclude failed students from the total marks using sumif()
2) i dont want to add extra column for percentage of each subject.
3) failed subject should be filled with any chosen color.

i am attaching sample data file.

thnx

[Special-K]

in N8
=SUMPRODUCT((G8:L8/G$7:L$7>=40%)*(G8:L8))

[Bo_Ry]

Maybe try at
N8 drag down
=SUMPRODUCT(G8:L8*(G8:L8>=G$7:L$7*0.4))

G12 drag to the right
=SUMIF(G8:G11,">="&G7*0.4)