Question

A new computer virus can enter the system through e-mail or through the internet. There is a 30% chance of receiving this virus through e-mail. There is a 40% chance of receiving it through the internet. Also, the virus enters the system simultaneously through e-mail and the internet with probability 0.15. What is the probability that the virus does not enter the system at all?

Answer 1

15 both e-mail and internet

15 e-mail only

25 internet only

-----------------------add

55 total

10-55=45 the probability that the virus does not enter the system at all.

Answer 2

15 both e-mail and internet

15 e-mail only

25 internet only

-----------------------add

55 total

10-55=45 the probability that the virus does not enter the system at all.