The questions are taken from Exam Master. Many are very abstract and obscure. 55% is passing on most, except Psych. Each core shelf has a curve of roughly 25% added. They are nothing to worry about, as you can't really properly study to get a good grade for them because they aer so abstract, except for the core or 2 that you want to be sure to ace. You'll do well on those because that's your area and you've been reading and doing questions all during the core, of course.

That would be the area you are applying for in residency.