I didn't learn Ivies commonly gave free rides until a while into my undergraduate at my state public university. I think what you're seeing is more an issue of questioning the specific assumptions that prevent the question from springing to mind, than it is knowing how to answer questions by searching the internet. Remember that their low-income parents and public school are probably doing very little or nothing to guide them through the applications process, and quite likely not even much to grok the sort of cultures where you have selection processes that require a lot of effort and domain knowledge, in general.

This is a non-trivial case of jootsing if you aren't already immersed in a culture that brings you most of the way to asking the question. It's a serious test of reflective intelligence, unlike SATs and acquiring grades and conforming to the college admissions process which are pretty much all about algorithmic intelligence (using Stanovich's terminology).