At present, 121 tons of goods need to be transported, [car a can transport 5 tons, 400 yuan], [car B can transport 8 tons, 500 yuan], [car C can transport 10 tons, 600 yuan] Suppose every car is full ① If there are 13 vehicles in total, how many are vehicles a, B and C? What is the freight? ② Can you tell me how to ship it and how much is the least freight?

At present, 121 tons of goods need to be transported, [car a can transport 5 tons, 400 yuan], [car B can transport 8 tons, 500 yuan], [car C can transport 10 tons, 600 yuan] Suppose every car is full ① If there are 13 vehicles in total, how many are vehicles a, B and C? What is the freight? ② Can you tell me how to ship it and how much is the least freight?

① If there are 13 cars in total, how many cars are there for car a, car B and car C? What is the freight? Car a can transport 5 tons, car C can transport 10 tons. The tonnage of car a and car C must be a multiple of 5. There are 121 tons of goods in total, which is odd. Car B can transport 8 tons, which is even. Therefore, the tonnage of car a and car C must be the mantissa of 5! Use 121 to subtract 5,15 respectively