Out of 17 applicants 8 boys and 9 girls. Two persons are to be selected for the job. Find the probability that at least one of the selected persons will be a girl.

The events of selection of two person is redefined as first is a girl and second is a boy or first is boy and second is a girl or first is a girl and second is a girl.
So the required probability:
= $\frac{8}{17}*\frac{9}{16}+\frac{9}{17}*\frac{8}{16}+\frac{8}{17}*\frac{7}{16}$

=  $\frac{9}{34}+\frac{9}{34}+\frac{7}{34}$
=  $\frac{25}{34}$