Why does 'whose' no longer precede an article? If 'whose' is equivalent to 'of which', it should be allowed to, should it not ?
While some dictionaries will state a definition of whose to mean of whom or of which, it is always best to also see how that definition works, rather than looking at those words and getting confused.
‘Whose lunch box is this?’ the teacher asked.
The children scratched their heads, wondering whose it was.
Peter Johnson was a very important businessman whose particular attention Charlotte did not readily favour.
In these three examples, an article does not follow whose because, as Janus and Edwin have noted above, whose by itself is an adequate determiner for the object and any my, the, a, this, or every is not necessary to convey further ownership.
Not to be confused with who’s, which can be followed by an article.