In what time will a train 320 m long cross an electric pole, it its speed be 144 km/hr?  Choose the correct answer:
A) 2.5 sec	B) 8.0 sec	C) 3.5 sec	D) 2.9 sec	E) 9.5 sec

Rationale: "speed = 144 * 5 / 18 = 40 m / sec time taken = 320 / 40 = 8.0 sec . answer : b"
Answer: B