Darn, I wrote Brussels. I was a little confused about what was meant by richest (and what's meant by city too). I think this needs to be defined a bit further.
this is by far the most inaccurate quiz I've taken in this site...there's no way London, Paris, Dubai, Moscow, Seoul, Mexico City or Sao Paolo didn't make this list...you have to specify what's your deal....if it's per capita, I might give you the benefit of the doubt, but if it's in gross total, you are sooo far away from the truth it's embarrassing....