A factory can have no more than 200 workers on a shift, but must have at least 100 and must manufacture at least 3000 units at minimum cost. How many workers should be on a shift in order to produce the required units at minimal cost? 

Let x represent the number of workers and y represent the number of units manufactured.

Find values of x and y for several points in or on the boundary of the shaded region. Include any “corner points,” where C is maximized or minimized.