A production family employs 20 workers on the day shift, 15 worker on the swing shift, and 10 workers on the graveyard shift. A quality control of consultant is to select 6 of these workers for in-depth interviews. Suppose the selection is made in such a way that any particular group of6 workers has the same chance of being selected as does any other group
a) How many selections result in all 6 workers coming from the day shift? What is the probability that all 6 selected workers from the day shift?
b) What is the probability that all 6 workers will from the same shift?
c) What is the probability that at least two different shifts will be represented among the selected workers?
d) What is the probability that at least one of the shifts will be unrepresented in the sample of workers?