A car and a train move in the same direction. The speed of the car is 4 m/s and the speed
of the train is 6 m/s. If it took the train from head to tail 1 minute to catch up with a mark
on one of the car’s tires, what is the length of the train? (After the head of the train caught
up with the car to the level of a mark on one of the car’s tires, it took the end of the train
1 minute to reach to the same level of the mark on the tire. How long is the train?)
答案：B