Would you be able to share that? Simple programming/algorithm questions are a dime a dozen, but I'm curious what a word probably that's appropriate to coders would look like.
that question is a bit of a turn-off to me. obviously "benchmark it, see what's slowest, and make it faster" is a correct answer, and so is a 40 page essay about browser rendering, minification, full page caching, fragment caching, AJAX, etc. have you tried anything more specific?
If you have examples of more specific questions, I'm glad to hear them. I would accept either of your answers, btw. Answers I have seen include "It is always SQL" and "make it ajax--ajax is fast."
The purpose is just to verify that they can put some ideas into writing, have a mental framework for debugging in place, and can verbally demonstrate any sort of familiarity with the technologies involved. It isn't a gotcha-type question that expects a specific answer.
edit: That said, your feedback is good and I will amend it to give more of an idea of how long a response is desirable.
Describe how you might approach researching, diagnosing, and reducing the page load time for a web page with poor performance.