For example, in tossing a coin, if the occurrence
of the head is considered a success, then occurrence of tail is a failure Each time we toss a coin or roll a die or perform any other experiment, we call it a
trial If a coin is tossed, say, 4 times, the number of trials is 4, each having exactly two
outcomes, namely, success or failure The outcome of any trial is independent of the
outcome of any other trial