These comments are on today's 4:40pm or so.

* 1st page says there are 165 and 2nd page has 150 points?

* Problem 2:
shouldn't we have "by strong induction..." instead of just "by induction..."?
Ok, I get the bug in the proof now that I read the solutions. The
claim is true, but the proof is false, because it assumes k=2 to
prove (simply speaking) n=2.

* Problem 12:
last sentence "Briefly indicate ... the the ..." (delete one of them)