Most exams vary and to be honest, knowing how many questions you're likely to get won't make a difference to your chances of passing. Would you study less if I told you there were 10 questions from all the skills measured and study more if I said 1000?
The best advice is to make sure you know everything required and have the relevant experience to back it up.
http://www.microsoft.com/learning/en/us/exam.aspx?ID=70-450#tab2
PT_UK http://redmanta.co.uk/blog Twitter: @redmantauk MCTS:WSS,MOSS,2010 MCITP:2010