Cheers Bodbo. A fun one - guessing is allowed. Here are twelve cities, the only way we have of identifying them is by the 3 most common family names found there. In order of popularity.
A) Brown, Smith, Patel
B) Williams, Johnson, Rodriguez
C) Garcia, Smith, Lopez
D) Smith, Brown, Tremblay
E) Tremblay, Gagnon, Roy
F) Diallo, Bah, Barry
G) Smith, Campbell, Brown
H) Yilmaz, Kaya, Demir
I) Jones, Smith, Williams
J) Smith, Jones, Kaur
K) Lee, Wang, Chen
L) Müller, Schmitz, Schneider
and for a bonus M) Nagy, Kovacs, Toth
A couple of these are quite easy some are more difficult, and two of them I didn't believe at first. The closest to twelve wins. They are all large cities.