2. [5 marks]. Formulate only, do not solve: Cleanco manufactures three types of disinfectants which it supplies to a variety of customers. For the upcoming month the total amount contracted of each are as follows: Disinfectant 1 2 3 Contracted Sales (1) 2000 3500 1800 Production takes place in two stages: Reactor 1 and Reactor 2. The number of hours available at each stage and the reactor processing time required per l for each type is given below: 1 Processing time per (hr) Disinfectant 1 0.10 0.04 Reactor 1 Reactor 2 Disinfectant 2 0.08 0.12 Disinfectant 3 0.02 0.06 Available hours 400 300 You will notice that there is not enough time available to satisfy all contracted sales. Consequently, Cleanco must buy some disinfectants from other manufacturers having excess capacity for resale to its own customers. This is more expensive than in-house production; per I costs are as shown below: Disinfectant 1 2 3 In-house Production Cost ($/1) 2.90 1.75 2.50 Outside Purchase Cost ($71) 3.25 2.50 2.80 What is the cheapest combination of production and purchase for satisfying all contracted sales? Formulate as an LP only; do not solve