Life Drawing 001

So I went along to a life drawing class Tuesday night.  Not the first time I've done life drawing, but it's been, like, 14 years since I the last (and only other) class.  It was an interesting experience, and I'm thinking of maybe going again next week.  
I didn't get a particularly good likeness; the model has great features, as she put it, "I have a jewish nose".  I wish I had been able to capture it better, but hey, (basically) my first time doing life drawing, so there's always more time to learn.  
The poses started out being 1 min, then 5 min, then 15 and finally 30.  I haven't included any of the really short sketches.  Try guess which is which (5, 15, or 30).