What's the platform number?

[smitster]

No: HPFGUIDX 6413

I'm probably just being picky, but why did Mother Weasley ask this in 
SS/PS when the family arrived at the station?  I've always had the 
impression that there was only one platform to board THE train to 
Hogwarts.  And from later books, we know that she must already know 
having been a student there.  Fortunately, little Ginny knows the 
answer (and she hasn't even been for all we know).  Being excited, 
she must have read the letter/ticket.

Surprisingly, I don't recall anyone questioning the capacity of the 
train when we had our lengthy discussions about the number of 
students.  (I could, however, have VERY easily missed it.)  Perhaps 
there are multiple platforms justifying Ms. Weasley's question.

Curious.  Very curious indeed...