Answer:
of the 4 people that have a sister, 2 of them have a brother
Step-by-step explanation:
probability of B given A
given that the person has a sister, what is the probability they have a brother
P (B/A) = 1/2
with this venn diagram
of the 4 people that have a sister, 2 of them have a brother
8+(x/-9)=9 subtract 8
x/-9= 1 multiply by -9
x= -9
