So as I'm learning some Korean Small Talk I stumbled across 2 different ways of saying "How are you?".

One of them is 잘 지냈어요?  /  잘 지났어? and the other option is "어떻게 지내세요?  /  어떻게 지내? 

Is there any difference or can I just use both of them. Or is one of them politer than the other.

And if I get asked this question and answer it, how do I say "And you?" ? 

And could you also give me some examples for answers to this question. I'm good, I'm soso, I'm bad etc. 

Thanks for answering ^-^