The event E ∩ F is also written as EF Very often we need to find the probability of  the event EF For example, in the
experiment of drawing two cards one after the other, we may be interested in finding
the probability of the event ‘a king and a queen’ The probability of event EF is obtained
by using the conditional probability as obtained below :
We know that the conditional probability of event E given that F has occurred is
denoted by P(E|F) and is given by
P(E|F) = P(E
P(F)F) ,P(F) 0
∩
≠
From this result, we can write
P(E ∩ F) = P(F)