The concept of probability is a quantitative way to describe the uncertainty of events at occur in our lives. The classical approach to probability describes the proportion of times that an event can be theoretically expected to occur. In the relative frequency approach, probability of an event is the proportion of times is the number of times an event is observed in a very large number of trials. Odds are expressed as a ratio.
Exhaustive events are events that include all possible outcomes of an experiment.
The marginal probability is the probability that a given event will occur. No other events are taken into consideration. Joint probability is the probability that two or more events will all occur. Conditional probability is the probability that an event will occur given that another event has occurred or will occur. Independent events occur when the occurrence of one event has no effect on the probability that another will occur.