Our world is full of uncertainty and probable events; such as storms, accidents, noisy communications, financial markets etc. We come across with data everywhere. Statistical interference and probabilistic modeling are the fundamental ways of analyzing data and making scientific predictions. Probability is a theory of predicting the chances of certainty or uncertainty of the events. In probability theory, an event is defined as an outcome of some experiment. For example – obtaining a head or a tail on the toss of a coin. Broadly speaking, the events are of two types: mutually exclusive and non-mutually exclusive. Let us go ahead and learn about non-mutually exclusive events in detail.