A train covers a distance of 12 km in 10 min. If it takes 7 sec to pass a telegraph post, then the length of the train is?  Choose one:  A) 298  B) 288  C) 140  D) 776  E) 991
Speed = (12/10 * 60) km/hr = (72 * 5/18) m/sec = 20 m/sec.   Length of the train = 20 * 7= 
<gadget id="calculator">20 * 7</gadget>
<output>140</output>
140 m.   Answer:140
<result>C</result>
A train covers a distance of 12 km in 10 min. If it takes 7 sec to pass a telegraph post, then the length of the train is?