As another example, suppose that a clinical trial is being run. Suppose that the probability that a patient recovers form her symptoms during the trial is p and that the probability is q=1-p that the patient does not recover. Let Y denote the number of patients who recovers out of n independent patients in the trial. Then the distribution of Y is also binomial with parameters n and p. Indeed, whenever an experiment consists of observing n independent trials with only two possible outcomes for each trial, the distribution of the number of trials with a particular one of the outcomes will be binomial with parameters n and p, where p is the probability of the one outcome that we are counting.