An exam has parts A and B, both of which must be completed. In part A you can choose between answering 10 true-false questions or answering 8 multiple choice questions, each of which has 5 choices. In...

An exam has parts A and B, both of which must be completed. In part A you can choose between answering 10 true-false questions or answering 8 multiple choice questions, each of which has 5 choices. In part B you can choose between answering 12 true-false questions or 6 multiple choice questions, 3 choices each. If one guesses on each question, what is the probability of getting a perfect score?