the length of the detroit mail is 120m and that of cincinnati is 80m.these two trains are running in the same direction with the velocities of 40 km/hr and 50km/hr respectively. the time taken by them to cross each other is?

• detroit mail=120m
  cincinnati mail=80m
  total length=120+80=200
  relative velocity=50-40=10km/hr=10*5/18=50/18m/sec
  time taken =200/50/18=72sec
• 12 years agoHelpfull: Yes(22) No(1)
• total length = (120 + 80) m = 200m = (200/1000)km
  relative velocity = 50-40 km/hr (trains are running in same direction)
  = 10 km/hr
  time = (200/1000)/10 hr = (1/50) * 3600 = 72 secs
  
• 12 years agoHelpfull: Yes(5) No(0)
• sorry there is a mistake 10km/hr is changed to m/sec
• 12 years agoHelpfull: Yes(3) No(0)
• km/hr has to be changed to m/sec as length of train is in m.....72sec is correct solution..
• 12 years agoHelpfull: Yes(2) No(0)
• length of the detroit mail=120m
  length of the cincinnati mail=80m
  total length of both the trains=120+80=200
  relative velocity=50-40=10
  time taken =200/10=20hr
• 12 years agoHelpfull: Yes(1) No(1)