Their argument is for all I care.

他们的争吵与我无关。

Eat whatever you like, for all I care.

你爱吃什么就吃什么，与我无关。

Handle it however you want, for all I care.

你想怎么处理这件事都行，与我无关。

You can do whatever you want, for all I care.

你可以随便做什么，与我无关。

Whether he attends the meeting or not, for all I care.

他是否来参加会议，与我无关。

You can eat dirt for all I care!

你吃屎都与我无关.

I prefer to have a “how-tasty-is-it” rule: if it is something really tasty, it can sit there for ten minutes for all I care - I will still eat it.

我这里倒有另一种说法：“美食法则”.如果手中的食物确实不错，我才在乎它掉在地上多长时间。