4. (20 marks) The following table gives the maximum flow between pairs of nodes. From/To 1 1 2 543 3 347 4 635 5 385 6 713 2 3 4 5 6 425 784 271 904 327 429 627 409 845 846 399 673 783 746 567 836 540 482 278 672 738 483 461 289 535 Use LINGO or the Excel Solver to determine the maximum flow through the net- work from node 2 to node 5. LINGO or Excel Solver models must include a definition of variables in the comments at the beginning. 4. (20 marks) The following table gives the maximum flow between pairs of nodes. From/To 1 1 2 543 3 347 4 635 5 385 6 713 2 3 4 5 6 425 784 271 904 327 429 627 409 845 846 399 673 783 746 567 836 540 482 278 672 738 483 461 289 535 Use LINGO or the Excel Solver to determine the maximum flow through the net- work from node 2 to node 5. LINGO or Excel Solver models must include a definition of variables in the comments at the beginning