Basic sets

I'm having problems with questions g) and k).

For g), apparantly the answer is i) but it seems to me they're all the same.If |b'| is a finite subset of an infinite set, then |b| must be an infinite set as N is infinite. Is there any difference between saying "b is infinite" and "|b| = infinity"?

For k), apparantly the answer is i) as well, but I still don't understand the notation. Could someone explain it through?.

Page in question: http://i38.tinypic.com/142ev41.jpg

>>34

The reason it was a gift is because it was on the Complex methods question, as opposed to the shared question. Meant complex analysis students got a 4th pop, which was rather unfair.

I couldn't be arsed to learn anything remotely applied/applicable, I deserved my 2.i. Was very pissed off with the Linear algebra though, 3 of them I answered totally apart from the very last bit, which was a bitch on them all. I had a word with the person who wrote them, Ben Green, he wasn't very sympathetic...