Here I'll present some problems that I've solved when attending this edX MOOC from MIT.
For more (much more) information you should enroll in the next session of this fantastic course at edX
Helpers functions and code skeletons presented here were provided by Professors Eric Grimson, John Guttag, Ana Bell and maybe it will change when you take the course. But if they are the same, do a favor for yourself and try to solve the problems first.