School assessment sheet

Members,

I need a little help with a complicated problem.

I would like to have a excel sheet to fill in my student assessment results.

Our rule is that if you have 80% of the questions, filled in correct you have a 6.

I don't know how to fix this in excel.

I can fill in the name, the total points (good answers) and after that i hope someone can help me to get the mark/score out of it.

The enclosure contains my filled in excel sheet.

Btw:

an example:

I filled in 16 correct answers out of a total from 20 answers and that means that my mark will be a 6.