Have you ever seen the cop shows where the good guy asks the criminal “what were you thinking?” The best answer I have ever seen is typically “Well, I wasn’t thinking.”
The thing is, it wasn’t really a question at all – it was a statement, something like “There is no good reason for you to have done this. What is your reason? Huh? Don’t I have one? I thought so.”
And, while you can understand the motivation of the police officer or prosecutor for asking, I have to admit, I always feel like it’s a cheap shot.
We have these questions in software testing (“Why is QA always the bottleneck?”) – and I’ve been getting them for years. So often, in fact, that I have a few stock answers.
After discussing this with my friends at SearchSoftwareQuality.com, they asked me to write an article to cover those impossible test questions – and just published it today:
How to answer unfair test questions
(Free registration required.)
I hope you find it helpful. If you are interested in more, please consider leaving a rating on the site; it could lead to a short series.

You forgot my favorite answer:
We DID find it, but dev chose not to fix it prior to launch!