For questions 21-23: In 2016, Grammy winner Adele performed…

For questions 21-23: In 2016, Grammy winner Adele performed in Phoenix, AZ. I was trying to get tickets to this event, but the moment that the online ticket vendor started dropping (selling) tickets, the system was so overwhelmed with ticket buyers that the web page would show an error. I had to refresh or reload the website several times before the “Purchase Tickets” page would show up. Suppose that X is the number of times that you had to reload and would see an error before the ticket page shows up, and that with each reload, there’s a 20% chance that you will see the ticket page instead of an error.