The speed ratio of the truck to the bus is 4:3. The two cars leave from a and B respectively. Two hours later, the truck is unloaded at station C on the way. At this time, the distance between the two cars is less than half of the whole journey Five out of nine, the bus continued to run and arrived at station C in a few hours

The speed ratio of the truck to the bus is 4:3. The two cars leave from a and B respectively. Two hours later, the truck is unloaded at station C on the way. At this time, the distance between the two cars is less than half of the whole journey Five out of nine, the bus continued to run and arrived at station C in a few hours

2 hours: 1-5 / 9 = 4 / 9
Bus line: 4 / 9x3 / 7 = 12 / 63
Bus speed: 12 / 63 △ 2 = 6 / 63
The bus continues to drive, and then passes: 5 / 9 △ 6 / 63 = 35 / 6 (hours)

The distance between the two places is 120 meters. The two passenger cars and freight cars are heavy at the same time. The two places leave relatively and meet in 2 / 3 hours. The speed ratio of passenger cars and freight cars is 4:5

The distance between the two places should be 120 km. What's the speed of the two cars?
If the speed of passenger car is 4xkm / h and that of freight car is 5xkm / h, then
2/3*（4x+5x）=120
9x=180
x=20
So: 4x = 80, 5x = 100
That is, the speed of passenger cars is 80 km / h, and that of freight cars is 100 km / h

A factory has 360 kg of a raw material and 290 kg of B raw material. It plans to use these two raw materials to produce 50 pieces of a and B products

A factory has 360 kg of type a raw materials and 290 kg of type B raw materials. It plans to use these two raw materials to produce 50 pieces of products a and B. It is known that 9 kg of type a raw materials and 3 kg of type B raw materials are needed to produce a product a and 4 kg of type a raw materials and 10 kg of type B raw materials are needed to produce a product B
(1) Please design the production plan of a and B products according to the requirements;
(2) If you can make a profit of 700 yuan for one product a and 1200 yuan for one product B, which of the above production schemes will get the largest total profit?
(1) If a factory can arrange to produce X pieces of product a, then (50-x) pieces of product B will be produced
From the theme {9x + 4 (50-x) ≤ 3603x + 10 (50-x) ≤ 290,
30≤x≤32．
There are three production plans: ① A30 pieces, B20 pieces; ② A31 pieces, B19 pieces; ③ A32 pieces, B18 pieces;
(2) Program (1) A30, B20 the biggest profit (45000 yuan)

A factory has 360 kg of type a raw materials and 290 kg of type B raw materials. It plans to use these two raw materials to produce 50 pieces of products a and B. It is known that one piece of a is produced
A product needs 9 kg of a raw material and 3 kg of B raw material. To produce a B product, it needs 4 kg of a raw material and 10 kg of B raw material. Q: if a is 80 yuan per kilogram and B is 120 yuan per kilogram, how can the design cost be the lowest?

Suppose we produce X pieces of product a and (50-x) pieces of product B; produce X pieces of product a need 9xkg of type a raw material and 3xkg of type B raw material; produce (50-x) pieces of product B need 4 (50-x) kg of type a raw material and 10 (50-x) kg of type B raw material; according to the meaning of the question, we can list the inequality group: 9x + 4 (50-x) ≤ 3603x + 10 (50-x) ≤ 290