Answer:
the value is 36
Step-by-step explanation: so you add
Answer:
5.78% probability that exactly 2 of them use their smartphones in meetings or classes.
Step-by-step explanation:
For each adult, there are only two possible outcomes. Either they use their smarthphone in meetings or classes, or they do not. The probability of an adult using their smartphone on meetings or classes is independent of other adults. So we use the binomial probability distribution to solve this question.
Binomial probability distribution
The binomial probability is the probability of exactly x successes on n repeated trials, and X can only have two outcomes.

In which
is the number of different combinations of x objects from a set of n elements, given by the following formula.

And p is the probability of X happening.
63% use them in meetings or classes.
This means that 
7 adult smartphone users are randomly selected
This means that 
Find the probability that exactly 2 of them use their smartphones in meetings or classes.
This is P(X = 2).


5.78% probability that exactly 2 of them use their smartphones in meetings or classes.
2n + 1
the number before n is the difference (what it goes up in), and the second is the ‘zeroth’ term: you take away the 2 you got from the first value, 3, and get 1 :)
Answer:
The answer is B
Step-by-step explanation:
10 × 75 = 750 minutes to file 100% of the files. (Approximately 12.5 hours)
= 0.7
70% of these files = 750 × 0.7 = 525 minutes.
Converting 525 minutes into hours, Jan would to take 8.75 hours to file 70% of the files.