Notice that the random variable Y is the number of successes observed in the n trials. Here, success is merely a name for one of the two possible...

Notice that the random variable Y is the number of successes observed in the n trials. Here, success is merely a name for one of the two possible outcomes on a single trial of an experiment. Before giving the denition of the binomial probability distribution, try to derive it by using the sample-point approach. How?