I think maybe you have to be a bit careful aiming for 1/X correct questions though -- it would be easy to pick something so obscure you could pretty much guarantee 1/X, but if it's apparent to the setters that they have no chance of "reading your mind", it might make that aspect less fun.

(Hmm, I'm not sure if I believe that now I've written it out, but I'll let it stand as a think-point anyway.)