1.
When the two cars meet for the first time, * * * the whole journey 1, of which A is the whole journey 100 km.
When the two cars met for the second time, * * * made three full trips, of which A made two full trips minus 80km.
Two cars travel three times, and one car should travel100× 3 = 300km.
So the whole journey of the two cars is 300+80 = 380km.
So AB is 380/2 = 190km apart.
2.
From the departure to the second encounter, the two cars walked three times at a time, which took 6 hours.
So 1 two-car train takes 6/3=2 hours.
So the distance between AB is (10+8) * 2 = 36km.
3.
When we first met, car A traveled 60 kilometers and car B traveled 1 10-60=50 kilometers.
So the speed ratio of the two cars is 60: 50 = 6: 5.
When the two cars met for the second time, * * * made the whole journey three times, 3 *1/kloc-0 = 330 kilometers.
A certain line is 330 * 6/(6+5) =180km.
When we met, it was 2 *11kloc-0/80 = 40km away from a city.
4.
When we first met, * * * did 1 time, of which A did 25 kilometers.
When we met for the second time, * * * made three full trips, of which A made 1 full trip plus 10 km.
Two people * * * walk three times, and A has to walk 25× 3 = 75km.
So 1 is 75- 10 = 65km.
So when we met for the second time, it was 65- 10 = 55km away from a city.
So the distance between the two meeting places is 60-55 = 5km.
5.
The speed ratio of passenger cars and trucks is 54:48=9:8.
When the two cars met again, * * * walked three complete journeys.
Among them, the bus has completed 3*9/(9+8)=27/ 17 times.
The distance from the midpoint is 27/17-1-1/2 = 3/34, which means 108km.
So the distance between AB is108/(3/34) =1224 km.
Another solution:
When they meet again, the bus is longer than the truck 108×2=2 16 km.
Passenger cars travel 54-48km more than trucks per hour = 6km.
So when they met again, the two cars drove for 2 16/6=36 hours.
* * * Line 36 *(54+48)=3672 km.
When the two cars met again, * * * walked three complete journeys.
So the distance between AB is 3672/3= 1224 km.