If you have outlined responses for all five questions, you will roughly get around a 50-60% score on each item. So, in the end you would be getting 250-300 points over the total of 500, assuming that each question is 100 points.
If you only answered two questions, your score, and assuming you got a 100 on each, you'd only get 200/500, instead of that 250-300/500.
