If $P(A) = \frac{1}{2}$ and $P(B) = 0$,then $P(A | B)$ is

Two integers are selected at random from the set $\{1, 2, \dots, 11\}.$ Given that the sum of the selected numbers is even,what is the conditional probability that both numbers are even?

In a certain town,$40\%$ of the people have brown hair,$25\%$ have brown eyes,and $15\%$ have both brown hair and brown eyes. If a person selected at random from the town has brown hair,what is the probability that they also have brown eyes?

If $A$ and $B$ are events such that $P(A) > 0$ and $P(B) \neq 1$,then $P(A \mid B^{\prime}) = $ . . . . . . .

$A$ parent has two children. If at least one of them is a boy,then the probability that the other is also a boy is:

If $P(A) = \frac{1}{2}$,$P(B) = \frac{1}{3}$ and $P(A \cap B) = \frac{1}{4}$,then $P(B/A) = $