It makes it easier if we change to actual numbers. If there are 100 children, there are 20 boys, 80 girls, 14 brown-eyed boys, 32 brown-eyed girls, 46 brown-eyed children.
a) P(girl)=0.80 or 80%.
b) If this means, given a boy, the probability of his having brown eyes, then the probability is 0.7 or 70%. If it means, given that the child has brown eyes (46 children), then 14/46=7/23=0.304 approx is the probability that it is a boy who has brown eyes (rather than a girl).
c) P(brown-eyed boy)=0.14 or 14% (14 boys out of 100 children have brown eyes).
d) P(brown-eyed girl)=0.32 or 32%.
e) P(brown-eyed child)=0.46 or 46%.
f) Given that the child has brown eyes (46 children), 32/46=0.696 or 69.6% is the probability that it’s a girl.