Stats/Probability problems

Thanks ahead of time guys,

Given P(A) = .3, P(B) = .5, P(A and B) = .2, find

a) P(A or B)

b) P(A|B)

c) P(A with bar on top)

A single card is drawn from a standard 52 card deck. Let A be the event "the card is a face card" and let B be the event "the card is a red card".

a) Find P(A) and P(B)

b) Find P(A|B)

c) Are A and B independent events? Explain why or why not.

I'm having troubles understanding these symbols etc. Can anyone somewhat explain the process I have to go through for each problem. Thanks.