# Thread: What means to implement in solving a probability question

1. ## What means to implement in solving a probability question

In a certain class of 30 primary school children there are 16 girls. There are 7 girls and 6 boys with fair hair. A pupil is selected at random to be a class captain. Find the probability that the class captain is
a) a girl whose hair is not fair
b) a boy with fair hair
c) has not ogt fair hair
d) is a girland has not fair hair

I'm not sure how to solve this because it seems as though the tree diagram and the venn diagram are not applicable?

2. Originally Posted by juliak
In a certain class of 30 primary school children there are 16 girls. There are 7 girls and 6 boys with fair hair. A pupil is selected at random to be a class captain. Find the probability that the class captain is
a) a girl whose hair is not fair
b) a boy with fair hair
c) has not ogt fair hair
d) is a girland has not fair hair

I'm not sure how to solve this because it seems as though the tree diagram and the venn diagram are not applicable?
Draw a 3x3 table, labelling the columns with 'fair hair' , 'no fair hair' and 'total' ,
the row with 'boys' , 'girls' and 'total'. Fill up the figures appropriately. Then everything should follow from here.