I don't give a damn

I

A: Do you know Linda is talking about the A project again?
B: Again? Whether she does it or not, I don't give a damn!
A: I know what you mean.
B: It's like beating a dead horse.

II

A: Don't you have to complete this work?
B: I don't give a damn. Joe is the one who messed it up. He should take care of it.
A: Well, at least you can help him.
B: Yeah. All right.