Well, a sufficiently intelligent person could guess that the moon is likely too small to have strong enough grav[realizes that Alicorn is looking at him in a weird way]... Just kidding. :-)

That was obviously a bad test.

There is a theory about how IQ tests should be designed. Most of the complaints in this discussion about why some IQ tests are not fair, are already known, and probably have been known for decades.

Of course it does not prevent people from ignoring those suggestions and making their own mistaken "IQ tests" anyway (especially if there is money and status to gain by doing so). Just like any amount of medical research cannot prevent people from making and selling homeopathics.