Consider again the original prototype example, modified by the
additional requirements (imposed by the company's marketing
department) that the daily production of product 
must be at
least 30 units, and that of product 
should exceed 20
units. These requirements introduce two new constraints into the
problem formulation, i.e.,
Attempting to plot the feasible region for this new problem, we get
Figure 5, which indicates that there are no points on
the 
-plane that satisfy all constraints, and therefore our
problem is infeasible (over-constrained).
