As for that question (which I just made up), it doesn't require you to know all the separate answers to the bits of the question; but they do help to narrow down your potential pool of answers the more you know. If you know that Baron Haussman redesigned central Paris in the 19th century, and you're being asked about a monument, you can take a guess and say Arc de Triomphe, which Haussman made a focal point by designing long, wide avenues leading up to it. Or if you're a literary person you might happen to know that Hugo wrote a poem about the Arc; or if you're a presidential history buff, you'll know that the flame from the Tomb of the Unknown Soldier, under the Arc, was incorporated into Kennedy's funeral at the request of Jackie, as they both visited the site in 1961. These all allow you to make a judgment on the likely answer, and the more separate answers you know, they less likely you are to guess the wrong thing. However, you could know the answer to each individual question, but if you don't have the intellectual sharpness to make connections between things, you might not get the answer. So it's knowledge plus intelligence, where pub quizzes tend to be just knowledge.