A student has exam in the discrete mathematics class tomorrow. The exam is divided in two parts. The first part includes only of true-false questions and the second part includes only of multiple choice questions. She determines that the probability of getting B or better on Part 1 is 0.8 and the probability of getting B or better on Part 2 is 0.6. She also determines that the probability of getting B of better on both parts is 0.5.
a) Compute the probability of getting B or better on Part 1 if she got B or better on Part 2?
b) Are the events "getting B or better on Part 1" and "getting B or better on Part 2" independent?