Two trains, each 120 m long, moving in opposite directions, cross other in 8 sec. If one is moving twice as fast the other, then the speed of the faster train is?
Choose the correct choice from the following
A) 72 km/hr B) 17 km/hr C) 60 km/hr D) 77 km/hr E) 46 km/hr
Let the speed of the slower train be x m/sec.   Then, speed of the train = 2x m/sec.   Relative speed = ( x + 2x) = 3x m/sec.   (120 + 120)/8 = 3x =&gt; x = 10.   So, speed of the faster train = 20 = 20 * 18/5= 
<gadget id="calculator">20 * 18/5</gadget>
<output>72</output>
72 km/hr.   72 km/hrnswer:72 km/hr
<result>A</result>
Two trains, each 120 m long, moving in opposite directions, cross other in 8 sec. If one is moving twice as fast the other, then the speed of the faster train is?