MIN 0.56X1 + 0.81X2 + 0.46X3
ST
0.2X1 + 0.5X2 + 0.4X3 >= 0.3
0.6X1 + 0.4X2 + 0.4X3 >= 0.5
1X1 + 1X2 + 1X3 = 1