"On which floor is the museum?"
Translation:Müze kaçıncı katta?
Yes, but it's less precise - the answer could not just be "on the third floor" but also "on the green floor" or "on the floor where the library is".
Kaçıncı is more specifically asking for the ordinal number of the floor and expects an answer like "on the third floor".
Good point, never thought of that, but this question could be answered the same way in English, "On which floor is the museum", "The green floor". So, I would expect "Hangi katta..." to be acceptable here as well. Thanks!