Answer:
This spyware is detected 66% of the time.
Step-by-step explanation:
We have these following percentages:
70% of the time, the spyware arrives via the internet, and in this case, is detected 60% of the time.
30% of the time, the spyware arrives via e-mail, and in this case, is detected 80% of the time.
What percentage of times is this spyware detected
Sum of 60% of 70%(arrived via spyware, detecte) and 80% of 30%(arrive via e-mail, detected). So
[tex]0.6*0.7 + 0.8*0.3 = 0.42 + 0.24 = 0.66[/tex]
This spyware is detected 66% of the time.