Question 1177964
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The probability that the virus will enter the computer via Email OR the Internet is


    p = 0.3 + 0.4 - 0.15 = 0.55.


The probability that the virus will not enter the computer at all is the complement to it, 


which is  P' = 1 - P = 1 - 0.55 = 0.45.      <U>ANSWER</U>
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Solved.