At a certain university, 30% of the students major in zoology. Of the students majoring in zoology, 60% are males. Of all the students at the university, 70% are males. a) What percentage of the students are males majoring in zoology? b) What is the probability that one randomly selected student is a male or is majoring in zoology, or both? c) What proportion of the males are majoring in zoology? d) Are the events "male" and "majoring in zoology" independent? Justify your answer.

please show the solution process(including what formula to use) thx!