This seems to be quite outside of the scope of a PDF, especially one generated by ColdFusion. Adobe Livecycle used to add functionality that might be useful, but it is quite an expensive solution for something that might be better served as a web page, etc.
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UPDATE: Of course, this won't prevent people from using "View Source" and cheating. For that you'd have to have a webserver and a server-side scripting language like CF with AJaX for the checking of scores and such.
Thanks Nic and WolfShade for this feedback.