A train 110 m long is running with a speed of 60 km/hr. In what time will it pass a trolley that is running with a speed of 12 km/hr in the direction opposite to that in which the train is going?
Choose the correct option
A) 4.31 B) 6.75 C) 7.92 D) 5.5 E) 6.5

Rationale: speed of train relative to trolley = 60 + 12 = 72 km / hr . = 72 * 5 / 18 = 20 m / sec . time taken to pass the trolley = 110 * 1 / 20 = 5.5 sec . answer : d
Answer: D