On the basis of this
relationship, we obtained probabilities of events associated
with discrete sample spaces We have also studied the
addition rule of probability In this chapter, we shall discuss
the important concept of conditional probability of an event
given that another event has occurred, which will be helpful
in understanding the Bayes' theorem, multiplication rule of
probability and independence of events We shall also learn
an  important concept of  random variable and its probability
distribution and also the mean and variance of a probability  distribution