In such cases, it is customary to call one of the outcomes a ‘success’
and the other ‘not success’ or ‘failure’ 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