A production facility employs 8 workers on the day shift, 6 workers on the swing shift, and 4 workers on the graveyard shift. A quality control consultant is to select three of these workers for in depth interviews. Assume the selection is made in such a way that any particular group of three workers has the same chance of being selected as does any other group. What is the probability that at least one of the shifts will be unrepresented in the sample of workers?