I've edited the OP to include this.
Cool - thanks! First time I did this I kind of skimmed through, and only when I read the second one and saw that it was different from the first did I go back and try to make guesses, so it's helpful to know in advance.
A piece I saw that Benjamin Todd adapted from THINK's module on charity assessment. Some of you may recall the network's recent launch.
cipergoth said that it should be emphasised that this isn't a trick question where the answer is they all worked or none did.
I thought Round 2 would have no effect and expected Round #5 to have no effect not a negative one, I got 6 out of 8 correct. How well did you do?
I recommend checking out the links and references. Gwern's comment there was also interesting.