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27. Alarm Clock - Redundancy: You have two alarm clocks. The rst one is successful 95% of the time and the second one is successful 60% of the time (it turns out your second one was actually less reliable than the rst). (a) Suppose you only remember to set the good alarm clock. What is the probability that it will succeed on the morning of an important exam? (b) Suppose you set both alarm clocks. What is the probability that at least one of them is successful on the morning of an important exam? (0) This practice of using a second device is called redundancy. Was there a signicant increase in the probability of getting to the exam obtained using the second alarm clock