We did this ages ago and I really can't remember how to do it! You will be loved forever if you can help me with this!

Question

The events A and B are such that

P(A) = 5/16, P(B) = 1/2 and P(A|B) =1/4

Find

(a) P(AnB)

(b) P(B'|A)

(c) P(A'uB)

(d) Determine, with reason, whether or not the events A and B are independant.

I know it's probably the easiest thing ever but I really can't remember what to do :(

Thanks in advance!