According to the KeePass note field for my Apple ID, my 3 questions are, "Pet", "Book", and "Street". I didn't write the whole things down, and as they usually appear in comboboxes, they aren't copyable, but one word is enough to identify them when challenged, so that's what I recorded. While the random strings that are my answers offer no clues to the full questions, I would guess they were something like, "What was the name of your first pet?", "What's your favorite book?", and "What street did you live on as a child?" Someone who is targeting a celebrity who has given broad-ranging interviews and whatnot could probably find out things like this pretty easily, and birth date is a given. People who know me could answer questions like these.
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I always pick the first three because the questions don't matter - I give random strings generated by Keepass as answers.
I think most people will pick the first three that are easy for them to answer and answer them accurately because they don't know any better. If they did know better, they'd do as I do, and there would be no issue.