The speed of car B is 4 / 5 of that of car a. the two cars meet at a distance of 30 km from the midpoint to find the distance between car a and car B

The speed of car B is 4 / 5 of that of car a. the two cars meet at a distance of 30 km from the midpoint to find the distance between car a and car B

solution
AB distance
30x2 ÷ (5-4) x (5 + 4) = 540km

The ratio of speed is 5:6. After meeting each other, car a starts to speed up. What percentage of speed does car a speed up? It's just 10
The two cars arrive at the terminal at the same time,

When we meet, the distance ratio is also 5:6
After meeting, the distance ratio between a and B is 6:5
At the same time, the speed ratio is 6:5
The speed of B is constant
5:6=25:30
6:5=36:30
A speed up: (36-25) △ 25 = 44%

A and B set out from a and B, and the speed ratio was 3 to 2. After they met, a increased the speed by 20% and B increased the speed by 30%
When a arrives at B, a is 25 meters away from A. how many km is the difference between a and B

Let a and B be x km apart
So the meeting point is 3x / 5km away from a and 2x / 5km away from B
After speeding up, the speed ratio between the two is 1
3*（1+20%）：2*（1+30%）=18:13
When a arrives at B, B passes by
2x/5/18*13=13x/45
According to the meaning of the title
3x/5-13x/45=25
x=25*45/14=1125/14km
A: the distance between AB and ab is 1125 / 14km, ≈ 80.36km
If you still have doubts, please ask

A and B start from AB and run in opposite directions. When they start, the speed ratio of a and B is 5:4. When they meet, a's speed decreases by 20%
In this way, when a arrives at B, B is 15 kilometers away from A. how many kilometers is the distance between a and B

The speed ratio is 5:4
We can assume that the total length is 9. At the speed of a and B, when a goes 5, B goes 4
The speed of a becomes 5 * 80% = 4 phr, the same as that of B
A finished the remaining four, B also went four
At this time, a finished nine, B finished only eight, and there was only one left
This one is 15 kilometers
So AB distance: 15 * 9 = 135 km