South Africa is one of the largest coal producing and exporting countries in the world. A company dealing with coal sources coal from four coalfields—Highveld, Emalehleni, Ermelo, and Klip River. The capacities of the four coalfields are:

Coalfield Capacity (tons)

Highveld 100 Emalehleni 150 Ermelo 180 Klip River 200 630 Coal is then transported to four steel plants in Thohoyandou, Cape Town, Upington, and Port Elizabeth. The demand at each of the four plants is:

Plant Demand (tons)

Thohoyandou 100 Cape Town 160 Upington 210 Port Elizabeth 130 600 The cost of transporting a ton of coal between locations are tabulated below along with available capacity at coal mines and exact demand requirements at the steel plants.

To (Cost, in thousands of Rand)

From Thohoyandou Cape Town Upington Port Elizabeth Highveld 470 1446 807 1110 Emalehleni 473 1540 927 1200 Ermelo 532 1543 1000 1155 Klip Rivier 554 1378 777 1044 Formulate this problem as a linear programming model and solve it using computer.