This is a must for people heading to trading firms, banks, or other financial service firms for interviews. These firms typically scout for a few skill sets. One is general brainpower, as hard as that is to measure. Another is the more difficult math in finance, derivatives pricing. This book covers both in a quick and easy format to let you see where you stand. Moreover, if you can master the material in the book then you will be ready for the majority of an entry-level interview.
The derivatives questions cover "plain vanilla" options pricing and some basic understanding of the principles behind the formulas. Most firms want to see that you know the terms in the Black-Scholes equation and how options prices depend on things.
The earlier part of the book I find even more impressive. It's a nearly comprehensive list of the brain-teasers you get in this process. That's where the employer is trying to measure general brainpower. Of course, a brain-teaser you haven't seen before will give you pause and maybe elude you in the stress of an interview. But after reading this book the answers could be at the ready. The set of brain-teasers through history is actually very small. That is after distilling all the variations on them such as whether you are weighing coins or cannonballs and such. And that set of puzzles, questions designed to test basic reasoning and logic, without depending on formal math, is well covered in this book. In fact, in many interviews I have only encountered one single brain-teaser that is not in this book (and it's not a very good one either).
Finally Mr. Crack inserts notes on the culture of banks which might scare or excite the prospective employee. This book is both good orientation and preparation for starting a career in finance.
It is still relevant and helpful ten years later. That said, there is one area this book totally misses (because of what's happened in the past ten years). That is programming questions. Especially in the past couple of years most interviews will look for some software development skill on top of the general brainpower and command of financial derivatives. Tests on C++ or OOP are common these days. For that material you have to look elsewhere.