You will see your grade posted next to the exams button. For High School and Career programs a 65% or higher is passing. For College Degrees and Courses 70% or higher is passing. Any multiple choice exams do have the option of one retake to get a better grade.
After taking all the exams in a class, the grades are averaged to show the class grade. You can pass a class even if you did not pass one exam, it all depends on the other grades and the average.
Good luck with your studies!!