It depends on how exacting "good" is. I don't think that there are any outright bad songs on those albums, but if we set the bar at "songs that I would go out of my way to listen to..."
I would put everything but QFF from PoM on there, so that's 42 minutes.
I would put tracks 1, 2, 6, 7 and 8 from PS on there, so that's 37 minutes. I could be talked into putting Flash of the Blade on there, too, which would bump it up to 41.
But I think the percentage also matters. 42/46 is a lot better by my lights than 41/51.