A train is 180 meters long, 20 meters per second. How long does it take for the train to cross the 320 meter long bridge?

A train is 180 meters long, 20 meters per second. How long does it take for the train to cross the 320 meter long bridge?

(180 + 320) △ 20, = 500 △ 20, = 25 (seconds), a: it takes 25 seconds

It takes 64 seconds for a train to pass a 572 meter long bridge, while it only takes 20 seconds for a train to pass a tree on the side of the road. How long is the train?
It's better to use arithmetic method, and write out all the processes in equation!

20x572 / (64-20) = 260m

There is a railway bridge with a length of 1000 meters. A train passes through the bridge. It takes 120 seconds for the train to get on the bridge and get off the bridge completely. The time for the whole train to be completely on the bridge is 80 seconds. What are the speed and length of the train?

Let the speed of the train be x m / s and the length of the train body be y m, and the relationship between them is listed. The equations are 120x = 1000 + y, ①, 80x = 1000-y, ②, which are solved by ① and ②: x = 10 m, y = 200 m. a: the speed and length of the train are 10 m / s and 200 m respectively