Question: From the flow out of the source and the flow into the sink in Example, we know that the maximum flow is at most 9. Is there a flow that achieves this upper bound?
Example: It is a little-known fact that ducks love pizza. (Note: not actually true.) On Take-Your-Duck-to-Dinner night, several students who live in the same dorm decide to take their ducks to the pizza place. There are too many students and ducks for a single car, so they take two cars. Figure shows local streets and alleyways represented as edges on a graph (the vertices are intersections), with the number of pizza-place-ward lanes given as edge weights.
