A survey of 100 Mercy students revealed 20 freshmen of which 4 had student debt; 25 sophmores of which 10 had student debt; 15 juniors of which 8 had student debt and 40 seniors of which 30 had student debt. A. What is the probability of selecting a student at random from this group who is a freshman or has student debt? B. What is the probability of selecting a student at random from this group who has no student debt? C. What is the probability of selecting a student at random from this group who is a sophmore or a senior?