Some of these professors write brilliant exam questions that really question your understanding of the fundamentals. I mean, wow, I had no idea how many blindspots I had when it came to stuff I had down.
A good source of these exams are Stanford
They seem pretty friendly about opening up their materials to society.
Hinton’s and Andrew NG’s coursera courses are another good source.
Unfortunately it seems most other universities don’t put of their exam solutions. If you know any other great sources, please post em.