A train traveling at 42 kms/ hr passes a cyclist going in the same direction in 9 secs. If the cyclist had been going in the opposite direction, the train would have passed him in 5 secs. Find the length of the train.

a) 75 meters b) 60 meters c) 90 meters d) 80 meters

• Ans: 75 meters
  Let the length of the train be x meter
  and the speed of the cyclist is y m/s
  Now when the train and the cyclist are in the same direction, the relative speed is :(35/3-y)m/s[converting 42km/h to m/s-35/3m/s]
  Now distance/relative speed =9 seconds
  Substituting the values, we get x+9y.....................(1)
  Similarly calculate the relative speed when they are in the opposite direction
  The relative speed is (35/3+y)
  Now distance/relative speed is equivalent to 5 seconds
  Substituting the values, we get the equation
  3x-15y=175.................................(2)
  Solving (1) and (2), we get x=75 meters
• 12 years agoHelpfull: Yes(6) No(9)
• a 75meters
• 8 years agoHelpfull: Yes(0) No(1)