At 7:20, car a and car B start from city a and city B respectively, and run in opposite directions. They meet at 10:40. At this time, car a takes 4 / 5 of the distance that car B takes 1. What is the average part of the whole journey per hour before the two cars meet? 2. After the meeting, the two cars continue to move forward at the original speed. Car B encounters fog in the middle of the journey and its speed drops to 3 / 5 of the original speed. Car a encounters rain on 14 / 15 of the whole journey and its speed drops to 5 / 6 of the original speed. As a result, car a arrives at city B and car B arrives at city a at the same time. When does car B encounter fog? If you want to have a good one, you must add more experience.

At 7:20, car a and car B start from city a and city B respectively, and run in opposite directions. They meet at 10:40. At this time, car a takes 4 / 5 of the distance that car B takes 1. What is the average part of the whole journey per hour before the two cars meet? 2. After the meeting, the two cars continue to move forward at the original speed. Car B encounters fog in the middle of the journey and its speed drops to 3 / 5 of the original speed. Car a encounters rain on 14 / 15 of the whole journey and its speed drops to 5 / 6 of the original speed. As a result, car a arrives at city B and car B arrives at city a at the same time. When does car B encounter fog? If you want to have a good one, you must add more experience.

1/（3+20/60）=3/10
5*（1-14/15）/（5/6）+5*14/15=4*x+4*(1-x)/(3/5)
x=3/5
That is, car B encounters fog when driving to 3 / 5 of the whole journey

It is known that the speed ratio of a and B is 2:3. It takes 11 / 2 hours for a car to walk the full distance. How many hours will it take for a car to meet each other

11/2×2÷（2＋3）
＝11÷5
= 11 / 5 (hours)

Car a and car B start from a and B at the same time and travel in opposite directions. When they meet, car a travels 7 / 8 of car B's distance, and car a travels less than car B
20 kilometers. How many kilometers is the distance between AB and a? How many kilometers does a car travel?

The distance ratio between a and B is 7:8
The distance of a is 20 kilometers less than that of B
So one portion is 20 kilometers
So a distance = 20 × 7 = 140 km, B distance = 20 × 8 = 160 km
Distance between the two places = 140 + 160 = 300 km a distance = 140 km

One morning, car a and B leave from a and B at the same time. They meet at 10 a.m., and then car a goes through 59 hours. After meeting, car B continues to drive to a at the original speed of 45 kilometers per hour, and arrives at a at 1 p.m. to find the distance between a and B

13-10 = 3 (hours), 45 × 3 △ 59, = 135 × 95, = 243 (kilometers); answer: the distance between a and B is 243 kilometers