Two trains, A and B, started simultaneously from opposite ends of a 200-mile route and traveled toward each other on parallel tracks. Train A, traveling at a constant rate, completed the 200-mile trip in 10 hours; Train B, traveling at a constant rate, completed the 200-mile trip in 6 hours. How many miles had train A traveled when it met train B? Choose the correct choice:	A) 70	B) 75	C) 87.5	D) 90	E) 92.5

Rationale: "as the ratio of the rates of a and b is 6 to 10 then the distance covered at the time of the meeting ( so after traveling the same time interval ) would also be in that ratio , which means that a would cover 6 / ( 6 + 10 ) = 6 / 16 of 200 miles : 200 * 6 / 16 = 75 miles . answer : b ."
Answer: B