Here's what we know from the article: (1) 40 question test, (2) Multiple choice, (3) She passed it with "60 out of 100" My assumptions: (1) It's graded on a si

Here's what we know from the article: (1) 40 question test, (2) Multiple choice, (3) She passed it with "60 out of 100" My assumptions: (1) It's graded on a simple "percentage right" basis, so 24/40 questions necessary right to pass, (2) 4 options for each question Her score on an individual test is a random variable X following a binomial distribution with 40 trials and chance of 0.25 for each trial. Her chance of passing by guessing randomly, P(X >= 24), is an infinitesimally small 2.826E-6. The probability that she fails all of the 960 tests, assuming independence of tests, is (1-p)^960. So the probability that she will pass at least one test is: 1 - (1 - p)^960 Plugging in p = 2.826E-6, the chance is still practically 0, so a naive guessing strategy would not work. However, under the above assumptions, she could practically guarantee her success by combining this guessing strategy with a simple test-taking strategy like eliminating 1 or 2 obviously wrong answers per question, or just remembering the answers to several of the same questions that are probably being recycled from test to test.