A new computer virus can enter the system through e-mail or through the internet. Thereis a 30% chance of receiving this virus through e-mail. There is a 40% chance of receivingit through the...

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