It's been a year and a half, but I'm sure not much has changed:
Logic test: Mark has three apples more than Cindy....
Math: Just mental calculations. A speed test. Get done as much as possible in the alotted time. No way to study for it.
Stupid test: I don't know what this one is called, but you see a symbol and have to match it to the identical symbol A, B, C, or D. It's a speed test and tests how quickly you can match stuff. The point? Unknown.
ATP test: About 50 questions from the ATP. Mostly regulations, approach questions, etc. Not difficult if you study the FARs and refresh yourself.
Systems test: You have 15 minutes (or 10, I can't remember) to read some pages that describe the engine fire system on the Dornier. Then you close the book and answer 5 questions about the system. Simple reading comprehension/memory stuff. No way to prepare for this one.
The tests are done at the beginning and you are quietly asked to leave during the break if you really screw them up. In my interview class of 8 pilots, nobody was asked to leave.