Two trains move in the same direction at speeds 50 kmph and 32 kmph respectively. A man in the slower train observes that 15 seconds elapse before the faster train completely passes by him. What is the length of faster train?
(a) 100m (b) 75m (c) 120m (d) 50m

• As both trains move in same direction, the relative velocity is (50-32)Km/hr
  => Velocity = 18Km/hr = 18*(5/18) m/s = 5m/s
  As 15seconds is the total time taken by the train,
  => Length of train = 5*15 = 75m
  Answer => (b)
• 12 years agoHelpfull: Yes(45) No(4)
• Train is moving in same direction (u-v) = (50-32)Km/hr
  speed = 18 Km/hr
  convert km/hr in m/sec = 18 * 5/18 = 5 m/sec
  Distance = Speed * time
  length of the train = 5 * 15
  = 75 m
  
  option (b)
• 7 years agoHelpfull: Yes(3) No(0)
• converting the velocity in m/s since option are in m
  50*5/18=125/9
  32*5/18=80/9
  difference between the two velocity = 5m/s
  d=v*t
  d=5*15
  =75m
• 7 years agoHelpfull: Yes(1) No(2)
• relative speed=50-32=18kmp=5m/s
  time=distance/speed=x/(5)=15
  length=1585=75m
• 7 years agoHelpfull: Yes(1) No(0)
• (b) 75m
  1. Find the relative speed of faster train w.r.t. slower train i.e. 50 - 32 = 18 kmph = 5 m/s
  2. length of the faster train = distance covered by the faster train in 15 sec = 5m/s * 15s = 75 m
• 6 years agoHelpfull: Yes(1) No(0)
• since both trains are moving in same direction, difference in speeed=50-32=18kmph
  which is equal to 18*(5/18)=5m/s
  time=15sec
  from the formula speed=distance/time,
  distance(length of train)=5(speed) * 15(time)=75m
• 6 years agoHelpfull: Yes(1) No(0)
• Mr venkateswar IYER S
  Is this 75m solution includes both the train lengths or length of one Train..??
• 7 years agoHelpfull: Yes(0) No(0)