According to a survey, 21% of residents in a country over age 25 had earned at least a bachelor's degree. You are performing a study and would like at least 10 people in the study to have earned a bachelor's degree.

Question

a)How many residents of the country do you plan t randomly select? This is 10/0.21 = 48
But I don't get the next part....
b)How many residents of the country do you have to randomly select to have a probability 0.89 that the sample contains at least 10 who have earned a bachelor's degree?