In a big university, 70 % of the faculty members like to give plus and minus grades (such as B plus and C minus). The other 30 % of the faculty members do not like the plus and minus system. The school newspaper randomly surveyed 200 faculty members for their opinions. What is the probability that more than half of the faculty members interviewed will be in favor of plus and minus grades? What is the expected number of faculty interviewed who answer the question positively?