Question 4 Three refineries send their gasoline product to two terminals. The refineries 1, 2, 3 have the capacities of 200.000,250,000, and 300,000 bb per day respectively, and they operate for 24 hours during the day. The demands at the terminals ( 7 and 8 ) are known to be 400,000 and 450,000 bb per day. Any dernand that cannot be satisfied from the refineries is acquired from other sources. The gasoline product is transported to the terminals via a network of pipelines that are boosted by three pumping stations. The Figure 5 below summarizes the links of the network together with the capacity of ench pipeline per diny (x1000) (a) How much flow should be passing through each pumping station? (b) Identify four different cuts. Show that the capacities of these cuts at least equals the maximal flow