Four contracts (A, B, C and D) to be awarded for a small roadway project. Six pre-selected contractors have provided their bid submissions for the different contracts as outlined below. Your senior engineer has asked you to determine which company should be awarded each contract to minimise the total project cost. They also stated that each contractor could only receive one of the contracts available. (a) Determine the assignment of the four contracts to minimise the total project cost using the matrix reduction method. Leighton Contractors: Contract A $ 550,000 > Contract B $ 120,000 > Contract C $ 240,000 > Contract D $ 410,000 Abi Group Contractors: > Contract A $ 700,000 > Contract B $ 90,000 > Contract C $ 270,000 Contract D $570,000 Thiess Contractors: Contract A $ 650.000 > Contract B $ 100,000 Contract C $ 180,000 > Contract D $ 350,000 John Holland Contractors: > Contract A $ 600,000 > Contract B S 140,000 > Contract C S 200,000 Contract D $ 600.000 RoadTek Contractors: > Contract A S 640,000 > Contract B S 120,000 > Contract C $ 290,000 > Contract D S 460,000 Seymour Whyte Contractors: Contract A $ 580,000 Contract B S 110,000 Contract C $ 250,000 Contract D $ 380,000