Mock Board

QUESTION!

I've been in my LVN program for 10 months, our class graduates in December of this year and our teacher just told us we have a mock board coming up. She also said that the mock board will be 50% of our entire med-surg grade. We have student contracts and are told in the beginning of our program what we needed to graduate and this was NOT included.... the class that graduated before ours also took the mock board but as practice, it didn't count for a grade. We arent getting any tools to study for it or even know what will be on it because it is coming from the state... my class is outraged like we aren't worried about our graduation enough.. any advice on how we can get this to go away???