SOLUTION: The probability of a email being spam is 0.1. What is the probability that out of 4 emails received at least one is not spam

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Question 372541: The probability of a email being spam is 0.1. What is the probability that out of 4 emails received at least one is not spam
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
Calculate the probability that all 4 are spam.
P%28SSSS%29=%280.1%29%280.1%29%280.1%29%280.1%29=0.0001
.
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P(all spam)+P(not all spam)=1
P(not all spam)=1-P%28SSSS%29
P(not all spam)=1-0.0001
P(not all spam)=0.9999