A and B two cars from the East and west to each other, after 8 hours meet, if a less than 1 km per hour, B more than 3 km per hour, 7 hours meet How many kilometers is the distance between the East and the west?

If a travels less than 1 km per hour and B travels more than 3 km per hour,
Then every hour, a and B will travel 3-1 = 2km more than before
The distance of 8 hours is 2 * 8 = 16 km,
This is 8-7 hours more than changing the walking method later,
That is to say, after the change, the distance they travel per hour and the service they pay for it
16/1=16 km/h
Therefore, the distance between East and West is 16 * 7 = 112 km,
The comprehensive formula is: [8 * (3-1) / (8-7)] * 7 = 112
Equation:
The design length is x km
8 hours, so the sum of the two speed = x / 8
When they meet in 7 hours, the sum of their speed is x / 7
When they meet in 7 hours, a travels less than 1 kilometer per hour. B travels more than 3 kilometers per hour
So the speed sum of the two increases by - 1 + 3 = 2
So x / 7-x / 8 = 2
x*(1/56)=2
x=112
So AB is 112 kilometers long

Party A and Party B travel from AB and meet each other in 8 hours. If Party A travels less than 1km per hour and Party B travels more than 3km per hour, they will meet in 7 hours to seek the whole journey

Let the speed of a be x1, the speed of B be X2, and the total distance be X. the following equation is obtained:
8X1+8X2=X
7（X1-1）+7（X2+3）=X
From the above: 8X1 + 8x2 = 7 (x1-1) + 7 (x2 + 3), we can get X1 + x2 = 14
Substituting X1 = 14-x2 into 7 (x1-1) + 7 (x2 + 3) = x gives x = 112
I don't know if it's right or wrong. I'll see for myself

12. Car a and car B run towards each other at the same time from 480 kilometers away, and meet in 6 hours. If the two cars speed up by 8 kilometers per hour, the distance between the two meeting points is shorter
4 km from the previous meeting point. It is known that car B is faster than car A. how many kilometers does car a travel per hour?

Let car a travel x kilometers per hour, car B travel (480-6x) / 6 = 80-x kilometers per hour, and the time for the second meeting is 480 / (x + 8 + 80-x + 8) = 5 hours, so (80-x + 8) × 5 - (80-x) × 6 = 4, and the solution is x = 44, so the speed of car B is 80-44 = 36 kilometers per hour, because the problem requires car B to be faster than car a

The distance between a and B is 300 kilometers. It takes 20 hours for a to complete the whole journey and 30 hours for B to complete the whole journey. Now, how many hours do they meet when they travel from a and B at the same time?

1 △ (120 + 130) = 1 △ 560 = 1 × 605 = 12 (hours); answer: meet in 12 hours

A and B two cars from the East and west to each other, after 8 hours meet, if a less than 1 km per hour, B more than 3 km per hour, 7 hours meet How many kilometers is the distance between the East and the west?