Q. The time a passenger train takes to cross another freight train is twice when the passenger train crosses the freight train running in opposite directions. What is the ratio of their speeds?

• let speed of freight train=x and speed of passenger train=y, and sum of their length =s so time=s/(x-y),when both are in same direction and time=s/(x+y) when oppsite direction.from question,s/(x-y)=2.s/(x+y) so solving this we get, x/y=3/1.
  so x:y=3:1
• 10 years agoHelpfull: Yes(18) No(4)
• 
  speed of freight train=x and speed of passenger train=y, and sum of their length =s so time=s/(x-y),when both are in same direction and time=s/(x+y) when oppsite direction.from question,s/(x-y)=2.s/(x+y) so solving this we get, x/y=3/1.
  so x:y=3:1
  
• 9 years agoHelpfull: Yes(2) No(0)
• Passenger train=x(len),freight train=y(len) x+y=s(assume)
  Here there are 2 instance
  1.Train in same direction
  2.Train in opposite direction
  Taking the 1 instance
  time=s/x-y----(i)
  Taking the 2 instance
  time=s/x+y---(ii)
  Compute both s/x-y=s/x+y
  we will get3:1
  
• 9 years agoHelpfull: Yes(0) No(6)