An express train traveling at 72 km/hr speed crosses a goods train traveling at 45 km/hr speed in the opposite direction in half a minute. Alternatively, if the express train were to overtake the goods train, how long will it take to accomplish the task. Assume that the trains continue to travel at the same respective speeds as mentioned in case 1.

(1) Cannot be determined
(2) 30 seconds
(3) 150 seconds
(4) 130 seconds

• let the length of the train A be x and that of train B be y
  Case 1: (x+y)/(72+45)*5/18=30
  because distance/speed=time . Since the trains are moving in opposite directions their speeds will get added. Also to connvet the speed from hrs to sec we multiply it by 5/18
  Here we get (x+y)= 39*5*5.
  
  Case 2: since the train has overtake the other they must be running in the same direction.
  therefore, 39*5*5/(72-45)*5/18= 130 sec.(when trains travel in same direction speed gets subtracted)
  
• 8 years agoHelpfull: Yes(2) No(0)
• cannot be determined
• 12 years agoHelpfull: Yes(0) No(2)
• it will be 130 sec
• 8 years agoHelpfull: Yes(0) No(0)