Two trains, each 100 meters long, moving in opposite directions, completely pass each other in 10 seconds. If one train is moving twice as fast the other, then what is the speed of the faster train (in km/hr)?
Choose the correct choice:	A) 48 km/hr	B) 56 km/hr	C) 64 km/hr	D) 72 km/hr	E) 80 km/hr
Let the speed of the slower train be x m/s   Then, the speed of the faster train is 2x m/s   The relative speed is 3x m/s   (100 + 100)/10 = 3x   x = 20/3   So, the speed of the faster train is 40/3 = 40/3 * 18/5= 
<gadget id="calculator">40/3 * 18/5</gadget>
<output>48</output>
48 km/hr   The answer is 48 km/hr.
<result>A</result>
Two trains, each 100 meters long, moving in opposite directions, completely pass each other in 10 seconds. If one train is moving twice as fast the other, then what is the speed of the faster train (in km/hr)?