Party A and Party B travel from A. B to each other at the same time. They meet 200 meters away from the midpoint of A. B. when they meet, the distance of B is two fifths of that of A. B. how many kilometers are there between A. B and B?

Party A and Party B travel from A. B to each other at the same time. They meet 200 meters away from the midpoint of A. B. when they meet, the distance of B is two fifths of that of A. B. how many kilometers are there between A. B and B?

If the total distance is 2S, then a takes S + 200m and B takes s-200m
So: 2 / 5 (s + 200) = S-200
The solution is s = 1400 / 3 (m)
Then the distance between a and B is 2S = 2800 / 3M

When they meet, the distance between a and B is 4 kilometers more than 7 / 15 of the whole journey. It is known that the speed ratio of a and B is 5:4

45 km
（7x/15+4）/5=[x-(7x/15-4)]/4

When they met, they were 8 kilometers away from the center of a and B. It is known that a's speed is twice that of B's,
Finding the distance between a and B

When they meet, they use the same time, so it must be that one walks more than 8 kilometers in half of the total distance, and the other walks less than 8 kilometers in half. So the faster one walks 16 kilometers more than the slower one
Some people know that the speed is twice as fast as the speed. It can be seen that the extra 16 kilometers is the distance for the slow one
So the distance between AB and ab is 16x3 = 48km