2. Joe's marks at the end of the semester are as follows: Tests = 85%, Quizzes = 83%, Assignments = 75%, Project = 90% The weighting of each category is: Tests= 40%, Quizzes= 20%, Assignment=10%, Project=10%, Exam=20% (6 marks) a) If he wants a final mark of 85%, what does he need to get on the exam