I don't know if that information is contained in a particular book, but it is certainly readily available all over the web.

Why do we care? Could Edison have had a similar interest, though focused more on his own business?

Separately, what good is knowledge of theory if you have no practical experience upon which to understand it? The candidates given this test were also supposed to be in line for the executive ranks. Having a general knowledge of geography, geopolitics and trade would seem to be fairly important.

It's also unclear from the article exactly how Mr. Edison interpreted or used the results. Frankly, it sounds like many of those quoted in the article were offended by being asked such "simple questions"... despite not being able to answer them. Perhaps Mr. Edison was interested in finding executives who didn't believe that common sense, mundane facts or important business details were beneath them and best left to others.