The first three are right, but you never defined A and B, i had to guess

The complement one is right

The powerset question is right, but put {} around everything you wrote

I believe the cartesian product one is wrong - try it again and remember that a cartesian product is a set containing ordered pairs.

I don't know what the set Workforce is, but I can tell that your last answer is wrong; here is why:

Let M = (Workforce / C), M cannot possibly contain anything in C, therefore it cannot contain Coop

M/B cannot possibly contain anything not in M, and Coop is not in M, so M/B cannot contain Coop