Three types of messages arrive at a message center. Ten percent of the messages are "high priority" forty percent are "normal priority" and 50 percent are "low priority". A) Find the probability that out of messages are not high priority. B) Suppose that messages arrive one at a time. Find the probability that messages are received before a high-priority message. C) Find the probability that out of 20 messages, 5 are high priority, 10 are normal priority and 5 are low priority.