For safety reasons, three different alarm systems were installed on the property of a famous movie star. Each of the three systems detects when a trespass occurs with a probability of 0.98 independently of the others.The movie star, obviously, is interested in the probability that when a trespass occurs, at least one of the three systems will detect it.What is the probability that when a trespass occurs, at least one of the systems will detect it?
Question
For safety reasons, three different alarm systems were installed on the property of a famous movie star. Each of the three systems detects when a trespass occurs with a probability of 0.98 independently of the others.The movie star, obviously, is interested in the probability that when a trespass occurs, at least one of the three systems will detect it.What is the probability that when a trespass occurs, at least one of the systems will detect it?
Solution
To solve this problem, it's easier to first calculate the probability that none of the systems detect a trespass, and then subtract that from 1.
Step 1: Calculate the probability that one system does not detect a trespass. This is simply 1 - 0.98 = 0.02.
Step 2: Since the systems operate independently, the probability that all three systems fail to detect a trespass is the product of their individual failure probabilities. So, we have 0.02 * 0.02 * 0.02 = 0.000008.
Step 3: The probability that at least one system detects a trespass is the complement of all systems failing to detect it. So, we subtract the probability we found in step 2 from 1. This gives us 1 - 0.000008 = 0.999992.
So, the probability that at least one of the systems will detect a trespass is approximately 0.999992.
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