Answer:
0.11% probability that you must ask 20 people to find one person without a social networking site
Step-by-step explanation:
We have these following probabilities:
75% probability that a millenial has a profile in a social netwok site.
25% probability that a millenial does not have a profile in a social network site.
What is the probability that you must ask 20 people to find one person without a social networking site?
The first 19 people have a social network site, each with a 75% probability.
The 20th person does not have a profile, with a 25% probability.
So
[tex]P = (0.75)^{19}*0.25 = 0.0011[/tex]
0.11% probability that you must ask 20 people to find one person without a social networking site
