Girls 20/(30+20)*5=2.

(2) Number the selected 3 men and 2 women as 1, 2, 3, 4 and 5 respectively.

Then the sample space is equal to (1 2) (1 3) (1 4) (1 5) (2,3) (2,4) (2,5) (3,4) (3. Event A means "there are exactly 1 female students among the two selected students", so A contains (1, 4) (1, 5) (2,4) (2,5) (3,4) (3,5) * * 6 basic events. So the probability is 6/ 10=3/5.