Two trains, each 150 m long, moving in opposite directions, cross other in 8 sec. If one is moving twice as fast the other, then the speed of the faster train is? Choose the correct choice from the following choices
A) 90 B) 98 C) 60 D) 88 E) 12

Rationale: "let the speed of the slower train be x m / sec . then , speed of the train = 2 x m / sec . relative speed = ( x + 2 x ) = 3 x m / sec . ( 150 + 150 ) / 8 = 3 x = > x = 25 / 2 . so , speed of the faster train = 50 / 2 = 25 * 18 / 5 = 90 km / hr . answer : a"
Answer: A