Total number of board members = 14 members.
Number of editorial board members arrangement possible without restriction = ${}^{14}{C}_5$ ways
= $\frac{14!}{5!(14-5)!}=\frac{14\times 13\times 12\times 11\times 10}{5\times 4\times 3\times 2}$
= $\text{2002 ways}$.
(a) With 3 girls and 2 boys
= ${}^8{C}_3{\times }^6{C}_2⟹\frac{8!}{3!(8-3)!}\times \frac{6!}{2!(6-2)!}$
= $56\times 15=840$
p(3 girls and 2 boys) = $\frac{840}{2002}$
= $\frac{60}{143}$
(b) Editorial board with all girls = ${}^8{C}_5$ ways
= $\frac{8!}{5!(8-5)!}=56$
p(all girls ) = $\frac{56}{2002}$
With all boys = ${}^6{C}_5$ ways
= $\frac{6!}{5!(6-5)!}=6$
p(all boys) = $\frac{6}{2002}$
p(either all boys or all girls) = $\frac{56}{2002}+\frac{6}{2002}=\frac{31}{1001}$.