By popular demand (and some visitors did demand hard!), I will provide answers to select sample questions. I will post the answers as a comment. So if you get stuck, just click Read comments for that blog entry to see if I have an answer.
Now, I’ll be honest. I get these questions from different sources besides my own collection. Often I don’t necessarily know the correct answer myself! This is not strange, since no quant — and nobody, for that matter — can know the answer to everything. I’ll do my best to come up with a solution, but in the interest of helping you, my dear reader, I’ll only write down correct solutions.
But I welcome my readers to contribute. If you have the answer, please write the word "ANSWER" in caps and on the first line by itself in your comment, so people know your comment contains the spoiler!