Set-covering models such as the original Western model in Figure 6.15 often have multiple optimal solutions. See how many alternative optimal solutions you can find. Of course, each must use three...

Set-covering models such as the original Western model in Figure 6.15 often have multiple optimal solutions. See how many alternative optimal solutions you can find. Of course, each must use three hubs because we know this is optimal. (Hint: Use various initial values in the changing cells and then run Solver repeatedly.)