That's all very well but ... if the JAA exams are based on one rate and the books from which I'm studying have another rate, it could mean getting a question wrong which, in my case, could be the difference between pass and fail!!!!
When the questions are all multi-guess, there is no scope for error; if they were written, I would still get some credit for the right method even if the wrong rate were used.
Cheers
Whirls