Two trains running in opposite directions cross a man standing on the platform in 27 seconds and 17 seconds respectively and they cross each other in 23 seconds. The ratio of their speeds is:

A. 1 : 3
B. 3 : 2
C. 3 : 4
D. None of these

• speed and time are inversly propronational so
  23-t1 and 23-t2 so 4:6 we get 2:3 then 3:2
• 11 years agoHelpfull: Yes(3) No(1)
• let length of trains are x and y
  so speed of the trains will be x/27 and y/17 respectively.
  now to cross each other time taken=23 second,
  so (x+y)/((x/27)+(y/17))=23
  (27*17)(x+y)/17x+27Y=23
  so, ((x/y)+1)/17(x/y)+27=23/27*17
  (x/y)+1=(23x/27y)+23/17
  4*(x/27)=6*(y/17)
  so,(x/27):(y/17)=3:2
  so ratio of speed of the train will be 3:2
• 12 years agoHelpfull: Yes(2) No(5)