In given problem, assume that 3 million out of 18 million users could not use their devices as cellphones, and that 1 million could not use their devices as a cellphone and for data device. What is the probability that a randomly chosen device could not be used either for data or for voice communication?
Problem
According to The New York Times, 5 million BlackBerry users found their devices nonfunctional on April 18, 2007.5 If there were 18 million users of handheld data devices of this kind on that day, what is the probability that a randomly chosen user could not use a device?