Assume that when adults with smartphones are randomly selected, 37% use them in meetings or classes. If 9 adult smartphone users are randomly selected, find the probability that exactly 2 of them use their smartphones in meetings or classes.
A. Assume that when adults with smartphones are randomly selected, 41% use them in meetings or classes. If 20 adult smartphone users are randomly selected, find the probability that exactly 12 of them use their smartphones in meetings or classes.
B. Assume that when adults with smartphones are randomly selected, 45% use them in meetings or classes. If 6 adult smartphone users are randomly selected, find the probability that at least 3 of them use their smartphones in meetings or classes