A total of 20 students participate in a drawing in which one name is selected. There're 7 seniors (4 men and 3 women), 8 juniors (2 men and 6 women) and 5 freshman ( 2 men and 3 women). Find out the probability of drawing the name of
a) a woman
b) a man
c) a woman who is a senior
d) a man who is a junior
e) either a man or a junior
f) either a senior or a junior
g) either a junior or a freshman