My school also gives ranks and marks. Marks are out of 100 for each subject, but for subjects such as maths adv & ext they made them out of 150. For us, they also tell us a band (like in the HSC), which in some subjects are 9)+ marks.
No idea why they do this though. Perhaps an indication of how we are going in comparison to our peers.
I think they give you the cumulative ranks for a reason + the cumulative marks.... and then the exam ranks + marks because they are the big assessments (worth a lot weighting wise).