Question

Yuto and Lian are at train stations 1,880 kilometers apart. Yuto boards a train heading east at an average speed of 220 kilometers per hour. At the same time, Lian boards a train heading west on a parallel track at an average speed of 250 kilometers per hour. How far has Lian traveled when the two trains pass each other?

Answer 1

To solve this problem you must apply the proccedure shown below:
 1. You have that the distance traveled by Lian is "x" and the distance traveled by Yuto is 1880-x.

 2. You have that the formula for calculate the speed is:
 V=d/t

 V1=d1/t1
 250=x/t1

 V2=d2/t2
 220=1880-x/t2
 
 Where d is the distance and t is the time.

 3. The problem says that Lian and Yuto board the trains at the same time, therefore:
 t1=t2
 x/250=1880-x/220
 x=1000 km

 Therefore, the answer is: 1000 km.

Answer 2

The correct answer is: D. 1,000.