Assume that when adults with smartphones are randomly selected, 61% use them in meetings or classes. If 9 adult smartphone users are randomly selected, find the probability that exactly 7 of them use their smartphones in meetings or classes.

Candice uses the function f(t)=t+100−−−−−−√ to model the number of students in her after-school program. the variable t represents days and f(t) represents the number of students. how many days does it take for there to be 15 students in her program? a. 225 days b. 125 days c. 325 days d. 115 days