to be honest, knowing the chicago convention in 1944/5 set up icao, and the principles of international flight we still hold today, is an easy few marks in a law exam. It's knowing the different classes of airspace, and clearences from cloud for VFR which actually need to be studied at length.
To say any more than 75% is a wasted effort is rubbish. To coast through life, just scraping through is awful, and you should always strive for the best.
I think my PPL were results were around the following:
Law: 85%
HPL: 100%
Aircraft Tech: 90%
Performance/Balance: 95%
comms: 100%
navigation: 100%
Met: 75%
it was 3 years ago, so may be off by 5% here or there
I'm happy with these reusults, and now these have formed the basis of the ATPLs which I am now studying. I dont think that more than 75% is a waste on ATPL exams, so will study my
off