The two trains depart from a and B stations at the same time. The passenger trains travel 40km per hour, and the freight trains 45km per hour. After the two trains meet, the passenger trains can travel 40km per hour, At the same time, the two trains leave from a and B stations. The passenger trains travel 40km per hour, and the freight trains 40km per hour. After the two trains meet, the freight trains continue to travel for 4 hours to A. how many km are there between a and B?

The two trains depart from a and B stations at the same time. The passenger trains travel 40km per hour, and the freight trains 45km per hour. After the two trains meet, the passenger trains can travel 40km per hour, At the same time, the two trains leave from a and B stations. The passenger trains travel 40km per hour, and the freight trains 40km per hour. After the two trains meet, the freight trains continue to travel for 4 hours to A. how many km are there between a and B?

Speed ratio of passenger car to freight car
=40：45
=8：9
It's necessary for trucks to complete the whole journey
4÷8/（8+9）
=4×17/8
=8.5 (hours)
The distance between a and B
=45×8.5
=382.5 (km)

Party A and Party B are facing each other between ab. Party A travels 45km per hour and Party B 40km per hour. Party A and Party B meet 12km from the midpoint to find the time of meeting

Encounter time = 12 × 2 ÷ (45-40) = 2.4 hours