Two trains of equal length when moving in opposite direction takes 5 sec. to cross each other completely and when moving in same direction takes 15 sec. Find the ratio of their speed.

• u/v=4/2=2:1
• 10 years agoHelpfull: Yes(13) No(3)
• lenght of train is = x
  so d = 2x
  nw wen trains mvng opposite tan speed = u + v =2x/5
  wen train movng sme dir. speed = u - v = 2x/15
  so ratio of speed is (2x/5)/(2x/15)=3:1
• 11 years agoHelpfull: Yes(7) No(8)
• time taken when moving in opposite direction is 5 sec
  time taken when moving in same direction is 15 sec
  
  ratio of time taken is 5:15 = 1:3
  t1: t2=s2 :s1
  therefore ratio of there speed is 3:1
• 9 years agoHelpfull: Yes(6) No(4)
• distance is d fixed in either case..
  speed of trains x1 and x2
  d/x1+x2=5 & d/x1-x2=15
  
  (d/x1+x2)=(1/3)(d/x1-x2)
  => 3(x1-x2)=x1+x2
  => x1/x2 = 2/1 i.e x1:x2=2:1 Ans.
• 9 years agoHelpfull: Yes(1) No(2)
• distance =x ;for 1 trains
  distance =2x ;for 2 trains
  s1=(2x/5);
  s2=(2x/15)
  ratio
  s1/s2=3/1
  ans: 3:1
• 9 years agoHelpfull: Yes(0) No(2)