In what time will a train 400 meters long cross an electric pole, if its speed is 144 km/hr	Choose one
A) 5 seconds
B) 4.5 seconds
C) 10 seconds
D) 2.5 seconds
E) none of these

Rationale: "explanation : first convert speed into m / sec speed = 144 * ( 5 / 18 ) = 40 m / sec time = distance / speed = 400 / 40 = 10 seconds answer : c"
Answer: C