Where can you find the solutions to the cell phone situation in the graph?

In the overlap of green and orange regions, however note that because the cell phones are indivisible physical objects, only the lattice points are possible solutions.

The solution(s) to a system of linear inequalities are those points which make all of the inequalities true and which can be found graphically in the regions of shaded overlap of the inequalities.

Depending on the situation, the number of solutions to a system of inequalities, can be none, infinite or anything in between.