It all depends on how the teacher is grading the paper.
Suppose he starts with a perfect score, say 100 percent.
If you get the first question (worth 3%) wrong, he deducts 3 percentage points from (takes 3 points off of / subtracts 3 from) the perfect score. So now you have a 97/100 score.
The grader will continue deducting points for wrong answers until he gets to th