The length of a train and that of a platform are equal. If with a speed of 90 k/hr, the train crosses the platform in one minute, then the length of the train (in metres) is:  Select: A) 400 B) 525 C) 750 D) 850 E) none

Rationale: "sol . speed = [ 90 * 5 / 18 ] m / sec = 25 m / sec ; time = 1 min . = 60 sec . let the length of the train and that of the platform be x metres . then , 2 x / 60 = 25 ⇔ x = 25 * 60 / 2 = 750 answer c"
Answer: C