Question: Consider the network shown in Figure. It reflects the paths lunch carts can take through the downtown Ra?cja (Slovenia) area during the lunch rush, from a napkin supplier to a compost pile.
(a) If you send nine lunch carts along the capacity-9 edge from the source, can they simultaneously reach the sink?
(b) Find a flow that sends a dozen lunch carts from source to sink, all at the same time.
(c) Starting with the flow you just devised, can you identify any paths with unused capacity along which additional lunch carts can be sent? By how much can you increase the total flow in this fashion?