What does it matter what their mark is?
How do you find out from someone you don't know? Find out their student number like a loser?
Also, when I talk to other students, I'm not concerned about their mark. It sounds like she is saying that this guy has 67%, so he doesn't know what he's doing. I bet if she talked to the guy first without knowing the grade, she probably wouldn't have guessed his/her grade to be that low.
I tutored a student who had an A in the class, but just wanted a tutor to learn more and understand better. A smart person who knows that an A means ****.
The school system should be based on a Pass/Fail basis. Fail is below 50 and pass is above 50, but the mark isn't posted. You have no clue how much better you are than anyone. You have to on your own decide whether you know your **** or not. For scholarships, they can have interviews. You might have an A, but when it comes to talking about the subject a week later in the interview, but you forgot everything... well your out of luck for $$$.
The person with 67% might only know 67%, but a year from now, the person might still know 67%, meanwhile the chick with 87% drops from 87->55%.
Who's the smart one now?
Put less emphasis on what other people got, and your position in the classroom.