Answer:
The probability mass function of X is:

Explanation:
A Binomial experiment has the following properties:
• There are a fixed number of trials (n).
• Each trial are independent of the others.
• Each trial has only two outcomes: Success and Failure
• Each trial has the same probability of success (p).
If a random variable X is used in an experiment and the experiment has all the above mentioned properties, then the random variable X is known as a binomial random variable.
Then the probability mass function of X is known as binomial probability distribution.
The probability mass function of X is:
