A goods train runs at the speed of 72 kmph and crosses a 270 m long platform in 26 seconds. What is the length of the goods train?
Choose the correct choice from the following:  A) 230 m  B) 250 m  C) 643 m  D) 832 m  E) 270 m

Rationale: "speed = ( 72 x 5 / 18 ) m / sec = 20 m / sec . time = 26 sec . let the length of the train be x metres . then , x + 270 / 26 = 20 x + 270 = 520 x = 250 . answer : b"
Answer: B