Cisco Career Certification exams scores are based on a point scaling system that is widely used in the industry. Your score can fall within a point scale of 300 to 1000 points. You are automatically awarded 300 points for beginning the test and can score up to 1000 points if you answer every question correctly on the exam. Please note that the specific number of points awarded to a given question varies on each of the different exams.
Passing scores are set by using statistical analysis and are subject to change. At the completion of the exam, candidates receive a score report along with a score breakout by exam section and the passing score for the given exam. Cisco does not publish exam passing scores because exam questions and passing scores are subject to change without notice.
The one thing I can say is to pass the simulations, they play a big part in the passing score. trying to relate a percentage of correct answers to a passing score is made difficult because of the grading that is done on the simulations and other simular types of questions.
You can also look here for more info: http://www.cisco.com/web/learning/le3/le11/learning_certification_exam_policies.html