Answer: The fraction of the children who have a dog also have a cat is

Step-by-step explanation: Given that
of the children within the city limits have a dog,
have a cat, and
have a dog and a cat.
We are to find the fraction of those children who have a dog also have a cat.
Let, S denote the sample space of the given experiment.
Then, n(S) = 1.
Let, event A and event B represents the fractions of children having a dog and a cat respectively.
Then, according to the given information, we have

The fraction of children who have a dog also have a cat is given by the conditional probability of event B given A.
That is, he required probability is

Thus, the fraction of the children who have a dog also have a cat is
