Two trains, each 100 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?  Pick one
A) 110 km/hr  B) 80 km/hr  C) 60 km/hr  D) 50 km/hr  E) 120 km/hr
Answer: Option C   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.   (100 + 100)/8 = 3x =&gt; x = 25/3.   So, speed of the faster train = 50/3 = 50/3 * 18/5= 
<gadget id="calculator">50/3 * 18/5</gadget>
<output>60</output>
60 km/hr.
<result>C</result>
Two trains, each 100 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?