(1) The two trains run from the two cities 480 kilometers apart. Train a runs 40 kilometers per hour, and train B runs 42 kilometers per hour. Five hours later, how many kilometers are there between train a and train B? (2) The distance between AB and a is 28 kilometers. A and B vehicles leave from AB in the same direction at the same time. Car a travels 32 kilometers per hour, while car B travels 25 kilometers per hour. Car B is in the front and car a is in the back. How many hours can car a catch up with car B?

(1) The two trains run from the two cities 480 kilometers apart. Train a runs 40 kilometers per hour, and train B runs 42 kilometers per hour. Five hours later, how many kilometers are there between train a and train B? (2) The distance between AB and a is 28 kilometers. A and B vehicles leave from AB in the same direction at the same time. Car a travels 32 kilometers per hour, while car B travels 25 kilometers per hour. Car B is in the front and car a is in the back. How many hours can car a catch up with car B?

1. Distance = 480-5 × (40 + 42) = 70km
2. Catch up = 28 (32-25) = 4 hours

Train a and train B run from two places 700 kilometers apart at the same time. Train a runs 85 kilometers per hour and train B runs 90 kilometers per hour. How many hours do the two trains meet?

700 △ 85 + 90 = 700 △ 175, = 4 hours. A: the two trains meet in 4 hours

Train a and train B leave 1050 kilometers apart at the same time. Train a travels 80 kilometers per hour, and after 2.8 hours, the distance between the two trains is 60% of the whole journey. How many kilometers per hour does train B travel?

1050 × (1-60%) / 2.8-80, = 420 ／ 2.8-80, = 150-80, = 70 (km); answer: car B travels 70 km per hour

The two trains leave 760 dry meters apart at the same time. Car a runs 110 kilometers per hour, and car B runs 80 dry meters per hour. After a few hours, the two trains meet?

4 hours