ere are exactly two mutually exclusive
          outcomes of a <a href="http://en.wikipedia.org/wiki/Bernoulli_trial" target="_top">Bernoulli
          trial</a>: these outcomes are labelled "success" and "failure".
        </p>
<p>
          For <a href="http://en.wikipedia.org/wiki/Bernoulli_trial" target="_top">Bernoulli
          trials</a> each with success fraction <span class="emphasis"><em>p</em></span>, the geometric
          distribution gives the probability of observing <span class="emphasis"><