1, this is a very simple mathematical model problem, because it is not multi-point and multi-variety transportation, and the quantity is only based on the number of vehicles and the number of kilometers traveled, and because the number of transportation times is not determined, it is subject to one time, so it is the most economical to perform the following transportation task schedule to complete the task.

Transportation task schedule

Name of goods | Starting point of transportation | Loading point | End point | Unloading point | Distance | Number of vehicles | Vehicle kilometer value

-Wood-|-Station-|-Site -|-9-|-4-|-36-

-Coal-|-Station-|-Steelmaking Plant -|-5-|-2-|- 10-

Consumables-|-Computer City-|-School -|-4-|-2-|-8-

-Rice-|-Grain and Oil Company-|-School -| S 1:-2-|-2-|-4-

-Rice-|-Grain and Oil Company-|-School -| S2:-3-|-2-|-6-

2. If the distance between the grain and oil company and the school is increased to 3 kilometers due to construction reasons, the original transportation plan will not be affected, but the transportation distance is 1 kilometer, and the vehicle kilometer value will be increased from 4 to 6. Note that the rice transportation from the grain and oil company to the school only starts S2 when S 1 cannot be used due to construction reasons (S1and S2 do not occur at the same time; Without S 1, there is S2).