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

• rel speed = 50-32=18 km/hr = 18000/3600= 5m/sec
  
  length of train = 5*15 =75 m
• 13 years agoHelpfull: Yes(30) No(0)
• let length of two trains be a+b
  speeds are 50 kmph = 50 *5/18=125/9 and 32kmph=32*5/18=80/9
  time taken by faster train to cross slower train=15sec
  15=9(a+B)/125-80
  (15*45)/9=a+b
  a+b=75m.
• 9 years agoHelpfull: Yes(2) No(0)
• Hey Nupur...the train is not passing the other slower train but the man...the man doent have any lenth.. so the answer straight away will be of faster train i.e. 75m
• 9 years agoHelpfull: Yes(0) No(0)