On the map with scale of 1:3000000, the distance between a and B is 20cm. Two trains leave from a and B at the same time Car a travels 130 kilometers per hour, car B 110 kilometers per hour. How many hours later do the two cars meet? Solution, O (∩)_ Thank you

On the map with scale of 1:3000000, the distance between a and B is 20cm. Two trains leave from a and B at the same time Car a travels 130 kilometers per hour, car B 110 kilometers per hour. How many hours later do the two cars meet? Solution, O (∩)_ Thank you

Actual distance: 20 △ 1 / 3000000 = 6000000cm = 600km
Meeting time: 600 ^ (130 + 110)
=600÷240
=2.5 hours

Train a and train B run from two places 600 kilometers apart at the same time. Train a runs 80 kilometers per hour. After 2.4 hours, the two trains are still 40% of the whole distance,
How many kilometers does car B travel per hour?

That is to say, they have driven 60% of the whole journey, that is, 600 * 60% = 360 km. Among them, a has driven 80 * 2.4 = 192 km, so B has driven 360-192 = 168 km, and the speed of B is 168 / 2.4 = 70 km / h
This is the traditional way of thinking

The first train is 60 km / h, the second train is 50 km / h, and finally meets at 30 km from the midpoint, so as to find the distance between the two places

30 * 2 / (60-50) = 6 hours
6 * (60 + 50) = 660km