Mr Rayon's easy probability questions

If $\displaystyle Pr(A)= 0.6$, $\displaystyle Pr(B)= 0.5$ and $\displaystyle Pr({A}\cap B') = 0.36$, find:

a) $\displaystyle Pr({A}'\cup B)$

b) $\displaystyle Pr(A\mid {B}')$

c) $\displaystyle Pr(B\mid{A}')$

As you guys may notice, I have trouble figuring these types of questions out if one of the probability sets is a A' and the other is B or when one is B' and the other is A'. It's SO confusing. I just don't see the logic. Would anybody be able to draw some venn diagrams for me to help me understand this basic concept? I'm really embarrassed to ask this question in school because I'm afraid it's too basic.

Anyway, any help would be appreciated dearly!