First of all I would like to thank Whizlabs for providing such a great source of mock exams.
There are total 6 mock exams all of 80 questions however the real Oracle exam contains only 70 questions. But it is good to do some extra questions so that you can feel that yes you can complete 70 questions of real exam in 2.5 hrs. Also there is explaination to each and every question. A good set of mock Exams.
One tip-> Main thing is Time management in real exam.
Last tip->During the preparation of your certification examination Never Ever Give Up