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 they are moving in the same direction so their relative speed is 50-32 i.e. 18kmph
  so length=speed*time
  l=(18*15)/(60*60) (converting sec into hours)
  l=0.075km or 75m
• 14 years agoHelpfull: Yes(16) No(0)
• ans is b)75m
  both train moving in the same direction so relative speed is 50-32=18kmph
  18kmph or 5m/sec
  d=s*t
  15seconds to take to cross the man completely in a slower train.
  d=5m/sec*15sec=75m
  
• 14 years agoHelpfull: Yes(9) No(1)
• 75
• 14 years agoHelpfull: Yes(4) No(2)