Check out the Marketing IQ Test.
I scored 120 despite not knowing anything about marketing. I only answered 10 out of 20 questions (the others, “don’t know”) but got all 10 right. I suspect that the low CEO score, if it’s representative, represents mainly overconfidence — the CEOs thought that they knew more than they actually know, and attempted to answer questions that they should have passed up. This to me is the most interesting implication of the test, though as it validates my biases about corporate executives it too should not be accepted uncritically.