A student is taking a multiple-choice exam in which each question has four choices. Assume that the student has no knowledge of the correct answers to any of the questions. She has decided on a strategy in which she will place four balls (marked A, B, C, and D) into a box. The marking on the ball will determine her answer to the question. There are 15 multiple choice questions on the exam. What is the probability that she will get:

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