Two trains start simultaneously from opposite ends of a 150-km route and travel toward each other on parallel tracks. Train X, traveling at a constant rate, completes the 150-km trip in 4 hours. Train Y, travelling at a constant rate, completes the 150-km trip in 3.5 hours. How many kilometers had Train X traveled when it met Train Y?
Choose the correct choice from the following options
A) 68 B) 70 C) 72 D) 74 E) 76
If the two trains cover a total distance D, then Train X travels (7/15)*D while Train Y travels (8/15)*D. If the trains travel 150 km to the meeting point, then Train X travels  (7/15)*150= 
<gadget id="calculator"> (7/15)*150</gadget>
<output>70</output>
70 km. The answer is 70.
<result>B</result>
Two trains start simultaneously from opposite ends of a 150-km route and travel toward each other on parallel tracks. Train X, traveling at a constant rate, completes the 150-km trip in 4 hours. Train Y, travelling at a constant rate, completes the 150-km trip in 3.5 hours. How many kilometers had Train X traveled when it met Train Y?