In what time will a train 140 meters long cross an electric pole, if its speed is 210 km/hr  Choose the correct choice from the following answers.
A) 5 seconds	B) 4.5 seconds	C) 3 seconds	D) 2.4 seconds	E) None of these
Explanation:   First convert speed into m/sec   Speed = 210*(5/18) = 58 m/sec   Time = 2.4 secondsistance/speed   = 140/58 = 2.4 seconds   Option 2.4 seconds
<result>D</result>
In what time will a train 140 meters long cross an electric pole, if its speed is 210 km/hr