Urgh seriously? A thread about this? If you're not passing them there's a reason for that.
Its not quite as easy as that, if the answers required are the obvious ones then most people would pass and the concept of cutting down (sifting) the number of applications wouldn't happen.
At the end of the day you have to pre-empt what answers they want, which is unknown.
There are a lot of possible conflicts in what they are looking for eg self-initiative versus team working, customer focus versus time constraints, flexibility versus guidelines/rules, assertiveness versus empathy etc etc.
I remember one questionnaire which had been tried and proven that I was given but I struggled to complete it in time. After, I did some research into the test and found the authors and their notes, including the statement that the test was an hour long to reduce any time pressure which would severely distort the results. But of course, someone that knew better had changed the time to 30 minutes thinking it would just make it harder and it would cream of the better candidates - wrong!