False Positives / Bayesian Stats

error probabilities test results: http://www.intuitor.com/statistics/BadTestResults.html

If they get access (like from finger prints) to a teacher's 4 digit iPad pin, how many different codes would they have...but to make it more interesting, how long would it take them to hack into the ipad given the disable feature for wrong passwords...what's the probability they would get in before they get locked out at each level...