In Present tenses^x, Mixed conditionals^x, Modals^x

I am confused by the difference of these sentences. A:If you finish the homework, you could go out with me. B:If you finished the homework, you could go out with me. Are they correct in grammar? If so, would you please tell me the difference? ^^^^^^^^^^^^^^^^ Yes Yoko, they are both...

- (The choice was his alone.) If he is saying, "Not that I would but if did, then this would happen". "If I open the door, a tiger will ..." is allowing that it is a more real chance. Even a mixed conditional is possible, "If I open the door, a tiger would ..."

If they stop making cars now, it would take 60 days to sell everything they have. What kind of structure is this? JTT: I think this even has a grammatical name; mixed conditional. How come the tenses don't match and it is correct? How do you know if this sentence is not a mistake? I can't...