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if a safety switch has a 1 in 10 chance of failing, how many switches would a company want to install in order to have only a 1 in million chance of them all failing at the same time

User Sameet
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2 Answers

2 votes
10^-n=10^-6

So n=6

Thus they will want to install 6 switches...


User Kayvan N
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8.2k points
6 votes
Because every individual switch has a 1/10 chance of failing, two switches will have a (1/10)*(1/10) chance of failing. Three switches will have a (1/10)*(1/10)*(1/10) chance of failing. This pattern will continue. Because
( (1)/(10) )^6 equals 1/1,000,000, 6 switches will give you a 1 in 1 million chance of all failing at the same time.
User Sonam
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8.8k points
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