Comments on Final: Took ~90 minutes to complete. I checked my answers with the solutions after the exam. I'll give you the answers I have that didn't fit the solutions or to problems whose solutions weren't written yet. Problem 1: Good problem. One quick thing, in the example, we say for all n in N but we don't in the actual problems -- should we either remove it from the example to be consistent (since in the problem description, we are already told that the domain of discourse is N). Took 4 minutes. Problem 2: Another good one. Took 3 minutes (mostly taken to write up the explanation) Problem 3: Do we define partially ordered coordinatewise vs. ordered lexicographically? i forgot the first one so didn't get that one. Other than that, part a was fine. Part b was fine too. I assume most students will probably pick to use c+s vs. the lexicographical ordered pair. For part c, it seems this could be a bother to grade since it's so openended and students can prove it numerous ways. I used the connected and acyclic definition of trees and it was easy using that def and structured too. I'm afraid that we may get a lot of hand-wavy arguments. Took 14 minutes. Problem 4: Do we define a losing strategy? Is it just basically a strategy you follow to guarantee you lose? In part e, there is some wording issues -- it says "if neither player has a non-losing strategy not have a winning strategy" -- should just say "if neither player has a non-losing strategy"? If i were to pick 5, I would probably pick a, b, e, f, g. Took 6 minutes. Problem 5: Part a was fine -- 11!/2!3!. Are we going to mention somewhere they can leave their answers with factorials and choose notation, etc? Part b was also fine -- 11!/2!3! - 9!/2! - 9!/3! + 7! Are these right? Took 5 minutes. Problem 6: I like this problem alot! Part a was fine. Part b - i ended up using stars and bars and got (2^11-1+2 choose 2). Which made part c easy. Took 7 minutes. Problem 7: Part a -- wording: we mean to say "before Carol picks two goats", not "before Carol picks a goat". Part b was fine too. I did it with a tree and got w=1/2. Part c was just like in pset problem. Took 9 minutes. Problem 8: Everything looked okay. Took 7 minutes. Problem 9: I had a lot of trouble with this one. I couldn't get part a to converge. I ended up with Sum(1->infinity) {n/Sum(1->infintity){1}} -- and I don't think this converges. But i'm not sure since all these sums got me a little confused. Part b I got something similiar to part a for E[R^2] and i think it does not converge so it works out here. I gave up after a while. Took 10 minutes. Problem 10: The expectation formula we use all the time for MTF is actually the third in the appendix isn't it? (the one where R must be natural number based?). Used Wald's and it came out fine. Maybe for part b, we should ask for the closed form. Otherwise, I feel like some students may give a ugly sum and hand wave why we should be able to find a closed form. The first formula I came up with involved flooring exponents and looked ugly. Took 8 minutes. Problem 11: Good problem. SHould state the bernoulli has probability p of being 1. Took 2 minutes. Problem 12: I choose the first one because i rememebered it from the in-class problems and I think it was the one that my table actually got to. I think it's shorter than the other proof will be. Both won't be too bad though. Took 3 minutes. Problem 13: It took me a while to understand what this problem wanted but it looks like what I have right now is a draft and will be revised on wording? OTher than that, a basic application of pairwise sampling. Took 5 minutes. OVERALL: The length is fine i think. I did however recognize a lot of the problems, if not from this term, then from past terms. It seemed pretty heavy on the last half of the term -- everything from problem 5 on were on counting/probability/etc. There is no structural induction like albert promised :)