Answer:
1,000 km
Explanation:
Assume that when two train pass each other, Lian has traveled x (km)
=> The time Lian has traveled when two trains pass each other is:
Time = Distance/ Rate = x/ 250 (hour)
As Lian and Yuto travelled from the two opposite train stations and the train stations are 1,880 km apart
=> When two train pass each other, Yuto has traveled 1,880 - x (km)
=> The time Yuto has traveled when two trains pass each other is:
Time = Distance/ Rate = (1,880 - x)/220 (hour)
As Lian and Yuto board at the same time, so that when two trains pass each other, the time both of them have traveled is equal
=> x/ 250 = (1,880 - x)/220
=> 220x = 250 x (1,880 -x)
=> 220x = 470,000 - 250x
=> 470x = 470,000
=> x = 1,000
So that, when two train pass each other, Lian has traveled x = 1,000 km