2  Binomial distribution
Consider the experiment of tossing a coin in which each trial results in success (say,
heads) or failure (tails) Let S and F denote respectively success and failure in each
trial Suppose we are interested in finding the ways in which we have one success in
six trials Clearly, six different cases are there as listed below:
SFFFFF,  FSFFFF, FFSFFF, FFFSFF, FFFFSF,  FFFFFS