Interesting, because many candidates would (rightly and safely) assume that you're asking if they already know the answer - not if (duh) they could just google it. And accordingly, to respond with "just google it" would mark them as a plodding, uninspired programmer - and definitely cost them points (or even outright sink the interview).

There are a surprising number of candidates & engineers that simply give up when they encounter a hard problem.

It sure is easy (and gratifying) to feel categorically superior to a significant portion of the people who walked in through that door with the idea of landing a job.

But Occam's Razor suggest that, rather than being a bunch of gutless dolts - they were (perhaps as a result of being bludgeoned by one soul-crushing interview experience too many) simply assuming a more conservative acceptance level to your question than you thought they were.