Probability → Basics → Vocabulary → Formula → Example Questions → Bernoulli Trial

An experiment that has only two possible outcomes is called Bernoulli trial. For example, Pass or Fail, Dead or Alive, Head or Tail etc.

For simplicity these events are called success (S) or failure (F). The probability of success is thus given by

And according to the fact that total probability is 1. We have, . And thus, the probability of failure is given by

**Example:** If the probability that a patient will survive is 0.3 then what is the probability that the patient could not survive?

**Solution**

Here, , So,

And,

So, the probability that the patient could not survive is 0.7.