Hey, the answer is 14 but I really think this is something you could have done yourself. You literally just have to count the number of lessons ... if you can't do that, I'm not sure why you're in this class or why you're skipping the lesson completely and just moving onto the quiz when you haven't read it yet?
So yeah, sorry if I sound rude but this is basic stuff, it's not even the beginning of the unit yet..