On average, 1 in 78 people have pancreatic cancer. How many people would you expect to have to ask before one says he or she has pancreatic cancer? By how many people would this number vary?

Not sure where to start with this one.

Bella want to know what the students at her school think of her show. which is the best group to survey to find this information a. go to the mall and ask all of the students she recognizes from school b. ask her viewers to call in durning an episode of the show c. get a list of students at her school from the office and use a random number generator to pick 30 of them d. get a list of students at her school from the office and pick the first 30 students on the list