I think that 知るかよ！ means "like I would know!"/"hell, if I know!" and that マジかよ！ means something like "[are you/is this] for real?"/"seriously?", but is there an underlying rule behind the ～かよ pattern seen at the end of sentences?
If I was to, for example, say （それを）食べるかよ, what kind of a meaning would it have?
Can ～かよ also be used as an ordinary question? Does it make a rhetorical question?