title: Calculating hours and minutes in python
body: <p>I have a task in which i need to calculate the runtime of a marathon. 
  I'm given this as a start point </p>
  
  <pre><code>start_hour = 3
  start_minute = 48
  length = 172
  </code></pre>
  
  <p>Basically the start is at 3:48 and it continues for 172 minutes.
  My task is to find when the marathon ends.The endtime should look like this format 3:48 with minutes and hour converted to string and put together with ":".
  I have spent like 1 and a half hour and i still can't manage to solve it.
  This is what i have come out with:</p>
  
  <pre><code>endhour = start_hour + (length // 60) 
  endminute = start_minute + (length % 60)
  end_minutee = endminute % 60
  format(endhour)
  endhourAsStr = str(endhour)
  end_minuteeAsStr = str(end_minutee)
  print(endhourAsStr + ":" + end_minuteeAsStr)
  </code></pre>
  
  <p>But when i print the final hour is shorter then it should be with 1 hour.
  I'm guessing that i need to do something with the > or &lt; but i really can't figure it out.I guess that i only need that final push.
  offtopic: I'm very new to proggraming i don't have experience whatsoever.</p>