What’s the Probability of an Impossible Event

Answer: To determine the probability of a certain event under a particular experiment, we consider evaluating the possibility of that particular event under that experiment. Thus, the formula of evaluating the probability of an event ‘M’ under experiment ‘E’, stands;

   P(M) = (Number of occurrence of event M under experiment E) / (Number of total possible outcomes of E)

   Now, if X be an impossible event, then no outcome of the experiment will be favourable to X and hence, X will have zero (0) occurrence under experiment E. Therefore, by formula:

   P(X) = 0 / (Number of total possible outcomes of E)

           = 0 [Since, number of total possible outcomes of E ≠ 0].