A train 150 m long passes a km stone in 15 seconds and another train of the same length travelling in opposite direction in 8 seconds.The speed of the second train is
a)60 kmph b)66 kmph c)72 kmph d)99 kmph

• Given that two trains are of same length i.e..150 mtrs
  first train passes the km stone in 15 seconds. here we have time and distance so speed=150/15=10 m/s
  we need to find out the second train speed.
  suppose the speed of the 2nd train is x m/s
  Relative speed of two trains is (10+x)
  ==> (150+150)/(10+x)=8
  ==> (300)/(10+x)=8
  ==> 300=80+8x
  ==> 300-80=8x
  ==> 220=8x
  :- x=55/2 m/s
  convert m/s into km/ph
  (55/2)*(18/5)=99kmph
  ;- The speed of the second train is 99Kmph
• 8 years agoHelpfull: Yes(1) No(2)