title: Algorithm/Function about computing taxi fare
body: <p>Let's say that a taxi charges $3.10 for the first fifth of a mile. Then for each additional fifth of a mile it charges half a dollar. For every minute of waiting or delay it charges half a dollar. However, this delay charge is applied instead of the mileage charge for each minute during which the speed of the taxi is slower than the brea-even point. The break-even point is the speed at which a fifth of a mile is driven in one minute. We are assuming the taxi goes at constant speed.
  I am trying to write an algorithm or function that takes in the total distance and total time travelled by taxi and outputs the fare. However, I am having difficulty factoring in the delay charge.</p>
  
  <p>So if the taxi is going at constant speed then ideally it would travel x miles during the time given (constant speed * time interval).
  If we subtract the actual miles travelled from this value, we would get the number of "wasted" miles that could have been travelled but were not. 
  And then I lose the train of thought and I am not sure where to go from there. Any help/hint would be appreciated. </p>