A cow was standing on a bridge, 5m away from the middle of the bridge. A train was coming towards the bridge from the ends nearest to the cow.Seeing this cow ran towards the the train and managed to escape when the train was 2m away from bridge.If it had run in the opposite direction, it would hit by the train 2m before the end of the bridge.What is the lenght of the bridge in meters assuming the speed of the train is 4times that of cow?
A)32 B)36 C)40 D)cant be determined

• 32 mtrs
  if x is distance of train from bridge and 2l is length of bridge, s is speed of cow, then
  
  (x-2)/4s =( l-5)/s
  4l-a=18 .......... (1)
  also
  (a+2l-2)/4s = (l+5-2)/s
  a-2l=14 ........(2)
  
  adding (1) and (2)
  2l=32 mtrs
• 11 years agoHelpfull: Yes(52) No(3)
• 32
  if L be the length of bridge. a is the distance between bridge and train.
  then 2L-a=18-------(1)
  L-a=-14--------(2)
  frm (1)&(2)
  L=32
• 11 years agoHelpfull: Yes(2) No(10)
• let b be the length of bridge from from cow to the near end of the bridge and a be the distance of the train from the bridge. (x speed of cow,4x speed of train)
  then the total length of the bridge 2b+10.
  (a-2)/4x=b/x
  =>a-2=4b........(1)
  (a+2b+10-2)/4x=(b+10-2)/x
  =>a-2b=24......(2)
  solving (1) and(2)
  b=11 ,therefore length of the bridge is 2*11+10=32
• 7 years agoHelpfull: Yes(1) No(0)
• can you please explain you answer more clearly jitendra singh?
• 11 years agoHelpfull: Yes(0) No(9)
• Let the length of bridge be 2x and the train is coming from an end at a distance of y from one end of the bridge.
  Let the speed of the cow is c , then speed of the train will be 4c.
  
  Now the time taken by the cow to escape from bridge and time taken by train to reach at first point will be equal i.e.,
  => (x-5)/c=(y-2)/4c.
  => 4x-y = 18.
  Now again the time taken by the train to hit the cow and time taken by cow to reach at second point will be equal i.e.,
  => (5+x-2)/c = (y+x+x-2)/4c.
  => 2x-y = 15.
  Solving both the equations, we will get the value of 2x as 32 that is the required answer.
• 7 years agoHelpfull: Yes(0) No(0)
• Ans is 32 mtrs
  Let x is the distance of train from bridge and 2l is the length of Bridge, s is the speed of Cow,
  then
  
  (x-2)/4s =( l-5)/s
  4l-x=18 .......... eq (i)
  and
  (x+2l-2)/4s = (l+5-2)/s
  x-2l=14 ........eq(ii)
  
  Adding (i) and (ii),we get
  
  2l=32 mtrs Ans.
• 2 years agoHelpfull: Yes(0) No(0)