<p>That’s helpful! Actually, I’m asking for my son because he is not participating on this forum. When he looked at the description of the courses and sample problems, he said 218 seems too easy, 215 he wasn’t sure about, and 217 he should take. It does correlate with what Princeton2014 said.
Also, one doesn’t have to be an IMO medalist to have been exposed to the material in these courses. Btw, I’m curious how many IMO medalists attend Princeton? I thought the majority of them go to H. And there only 6 each year anyway.</p>