One student asked me about these, as they were "posted" for a few minutes, so here is the answer that I wrote to this student:
Those are from prior years, and there was a need for a complete record of B8b, and that was
the easiest way for me to download them so that I had such a record (to do it without
bothering anybody else). They were thus "posted" for a few minutes.
I can post them again because I don't mind your having them, BUT I do not vouch for
anything in there being relevant for the current course---i.e., you are welcome to use them
if you want, but I make no promises whatsoever as to whether they will be helpful. They
were not posted there for revision, though also note that the practice exam will be ready
soon, and that is posted for revision.