# Conditional probability

In probability theory, conditional probability is the probability of an event occuring, given that another event has occurred. Usually this is written as ${\displaystyle P(A\mid B)}$. This is read as "probability of A given B". The two events need not be related. They also need not occur at the same time. In the most general case,
${\displaystyle P(A\mid B)={\frac {P(A\cap B)}{P(B)}}}$