A and B trains leave from AB for 5 hours at the same time. After meeting, the two trains run at the original speed for 4 hours and arrive at B. It is known that a is 10km / h faster than B?

Although there is no information in the title, what can be guessed is the distance between ab. suppose that the speed of a and B cars is x and Y respectively, there are: 4x = 5Y, X-Y = 10, x = 50km / h, y = 40km / h. The distance between AB and B is: S = 50x9 = 450km

A and B trains leave from a and B at the same time. They first meet at a distance of 98 km from a, and then they meet each other
A and B trains leave from a and B at the same time. For the first time, they meet at 98km away from A. after meeting, they continue to move forward and return to their destination immediately. For the second time, they meet at 48km away from A. how many kilometers are there between a and B?
Be very specific about why.

If the distance between a and B is YM and the speed of a and B is VA and VB respectively, the following equation can be obtained:
①、x/（VA+VB）=98/VA
②、3x/（VA+VB）=（x+48）/VB
① Compared with formula 2, formula 3 is VB = VA (x + 48) / (98x3) 3. By taking formula 3 into Formula 1, VA can be reduced and x = 171m can be solved

The speed ratio of the car to the train is 4:5. They travel from two places at the same time and meet at the place 12 kilometers away from the midpoint. How many meters has the train gone?

The distance ratio is equal to the speed ratio
When we meet, the distance ratio of car to train is also 4:5
When we met, the train traveled 12 * 2 = 24 kilometers more than the car
The train goes: 24 / (5-4) * 5 = 120 km

The speed ratio of the car to the train is 4:5. They travel from two places and meet 12 kilometers away from the midpoint. At this time, the train runs several thousand meters

Because the car and the train start at the same time, it takes the same time for them to meet
The distance ratio of car to train is 4:5
If the distance of the car is 4x, the distance of the train is 5x
According to the conditions given in the question, we can see as follows:
5x-4x = 12 + 12 = 24
X=24,5X=120
That is, the train traveled 120 kilometers
I hope my answer will help you

A and B trains leave from AB for 5 hours at the same time. After meeting, the two trains run at the original speed for 4 hours and arrive at B. It is known that a is 10km / h faster than B?