Question 597204
there are 84C8 ways of getting 8 reports from 84 people


a) no reports from 10 of the people means 8 reports from 74 people ___ 74C8


so probability of none from the 10 is ___ 74C8 / 84C8



b) is similar ___ 8 reports from 20 is ___ 20C8


so probability of all 8 from the 20 is ___ 20C8 / 84C8