The two trains leave from a and B at the same time and meet at a distance of 50 km from the midpoint 5 hours later. It is known that the speed of the local train is 5 / 7 of that of the express train. What are the speeds of the express train and the local train? How many kilometers are there between a and B?

The two trains leave from a and B at the same time and meet at a distance of 50 km from the midpoint 5 hours later. It is known that the speed of the local train is 5 / 7 of that of the express train. What are the speeds of the express train and the local train? How many kilometers are there between a and B?

50 × 2 / 5 / (7-5) = 10 km
10 × 5 = 50 km
10 × 7 = 70 km
(50 + 70) × 5 = 600 km

The fast and slow trains start from the two cities at the same time, and meet at 18 kilometers away from the midpoint after 4 hours?

(70 × 4-18 × 2) △ 4, = (280-36) △ 4, = 244 △ 4, = 61 (km); a: the local train runs 61 km per hour

The two fast and slow trains leave from a and B at the same time. Four hours later, the two trains meet at a distance of 18 kilometers from the midpoint. The fast train runs 54 kilometers per hour. How many kilometers are there between a and B?

The two fast and slow trains leave from a and B at the same time. Four hours later, the two trains meet at a distance of 18 kilometers from the midpoint. The fast train runs 54 kilometers per hour. How many kilometers are there between a and B?
4-hour journey of express: 54 × 4 = 216 (km)
General: 216-18 = 198 (km)
Total length: 198 × 2 = 396 (km)
The distance between a and B is 396 kilometers