A. B: the distance between the two places is 15 kilometers. One car is 50 kilometers per hour and the other is 40 kilometers A. B is 15 kilometers apart. One car starts from a at 50 kilometers per hour and the other at 40 kilometers per hour. At the same time, they start in the same direction. After a few hours, the two cars are 30 kilometers apart

A. B: the distance between the two places is 15 kilometers. One car is 50 kilometers per hour and the other is 40 kilometers A. B is 15 kilometers apart. One car starts from a at 50 kilometers per hour and the other at 40 kilometers per hour. At the same time, they start in the same direction. After a few hours, the two cars are 30 kilometers apart

The two cars are facing each other
When the distance between the two vehicles is 30 km, the two vehicles drive together
S = 15 + 30 = 45 km
Then the driving time of the two vehicles is
45 / 90 = 0.5 hours
So half an hour later, the two cars were 30 kilometers apart

A. B is 15 kilometers away from each other. One car starts from a at a speed of 50 kilometers per hour, and the other car starts from B at a speed of 40 kilometers per hour. Both cars start at the same time and travel in the same direction from B to a______ The distance between the two cars is 30 kilometers per hour

When two cars start at the same time and travel in the same direction, the first car travels 50-40 = 10 kilometers more than the second car per hour, and it is 15 kilometers apart at first. Then 30-15 = 15 kilometers, it takes 15 △ 10 = 1.5 hours, and the two cars are 30 kilometers apart