Pyroxene, what are the odds for you to flop a pair (hole cards) while villain flops a higher pair (with his hole cards that both are above yours) in a heads up match?

So basically like:
You hold 78, villain holds QJ, What are the odds for you to flop a 7 or an 8 while villain flops a Q or a J?

And what are the odds if he's holding like Q-4?