Two trains of equal lengths are running at speeds of 30 kmph and 60 kmph. The two trains crossed each other in 30 seconds when travelling in opposite direction. In what time will they cross each other when travelling in the same direction?	Choose the most appropriate option:
A) 90	B) 88	C) 66	D) 55	E) 11
Let the length of each train be x m.   (x + x) / (60 + 30)5/18 = (750 * 18) / (30 * 5)= 
<gadget id="calculator">(750 * 18) / (30 * 5)</gadget>
<output>90</output>
90 sec.   90nswer: 90
<result>A</result>
Two trains of equal lengths are running at speeds of 30 kmph and 60 kmph. The two trains crossed each other in 30 seconds when travelling in opposite direction. In what time will they cross each other when travelling in the same direction?