use of mark or marks

[englishquestion]

1) I couldn't complete the 10 marks paper( Is it "Marks or "Marks",also should it be "the" or "my paper",I mean exam paper in this sentence)

2) On the first day of my exams (Should it be "exams" or "exam",also "The" or "My" and why?).

[euncu]

***neither a teacher nor a native-speaker***

1-worth ten marks.

2- If you take more than one exam in a day, it should be "exams".