The probability of x successes P(X = x) is also denoted by P(x) and is given by
P(x) = nCx qn–xpx,    x = 0, 1, , n (q = 1 – p)
This P(x) is called the probability function of the binomial distribution A binomial distribution with n-Bernoulli trials and probability of success in each
trial as p, is denoted by B(n, p)