15.6.11 Definition and properties of probability

Problem: An exam is conducted in the form of a test, consisting of ten questions, each of which has four possible answers, among them exactly one is correct. To pass the test "successfully", at least 3 questions must be given correct answers. In case of failure of the first attempt of passing the test, one retake is allowed in the same form. Find the probability of passing the exam (immediately or after a retake), if the examinee chooses all the answers randomly. Multiply the found value by 1000 , round up to the nearest integer and write the obtained value as an answer.