https://www.gregmat.com/quizzes/quiz/timed-quant-practice-hard-section-2-sample-test-6 (Question 8)
the solution in the video asks for n if the expected value is the price of the ticket. I received a version of the quiz where the expected value is 0. In my calculations this was 11.5 which is 12, so the correct answer choice must be updated to reflect the change in the problem statement