It's About Showing, Not Knowing

Microsoft, Google, and others are known to ask some "trick" questions in job interviews, which (unsuccessful) candidates will complain have nothing to do with the position they're applying for. There may even be some hesitation about applying for a position at a company that includes questions such as, "how many golf balls would fit into a school bus?"

The point of these questions is not to humiliate you, or force you to fail an otherwise flawless interview. Any proficient candidate could probably answer the technical questions directly from memory, and asking such questions only helps to establish that a candidate has the prerequisite knowledge that qualified candidates need to possess. After one of these standard textbook answers is delivered, the candidate may be asked to deal with unexpected variations to see whether they can solve more of a real-world problem. This is the first part of verifying that the prospective employee hasn't just memorized answers about common topics, but truly understands how the solutions work.

The trick questions are also part of this process of assessing the candidate's analytical skills. They're not necessarily looking for you to provide the correct answer. They already know it's a tricky question, and that you might not answer it correctly in the stress of an interview. All they want to see is how you might work out the solution.

Don't bother with websites which list the trick questions and memorizing the answers. Instead, put more time into bolstering your knowledge of the fundamentals, and then practice this knowledge by applying it to some real or made-up projects. You're not going to be hired because you knew how many piano tuners there were in Chicago, or why manhole covers are round, but more because you could deduce a reasonable answer.

I said reasonable and not correct. In real life, you will probably have more time to research, come up with multiple approaches, and also discuss with colleagues. That process will probably uncover a correct or good answer. However, you need to demonstrate at the interview that you are capable of aligning your thoughts correctly so that they will eventually arrive at a good solution.

We can only memorize things which have happened. The real world, especially in the world of high-technology, is often about inventing the future, and those are different skills than the ones that typically helped you pass exams in school.

It's all about showing how well you understand, and how well you can create a better solution.