# 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

1
by kirthi1
the ratio of the speed is? we need to find that out?
can you please make the question more clear...

• Brainly User
2014-10-28T21:36:18+05:30
Let the lengths of the trains be x, y. Then the velocities of the trains are x/27, y/17. When they cross each other each one has to cover the other train's length and its own length hence the relative velocity is (x+y)/23=x/27+y/17. Solving this you get x/y=81/34
In this case since any one of the trains has to travel a total distance of x+y in 23 seconds it's (x+y)/23
woah. ur absolutely rite :O
Yup got it.. thanx..
no this is not the correct answer
Let the speeds of the two trains be x m/sec and y m/sec respectively.

Then, length of the first train = 27x metres,

and length of the second train = 17y metres.

27x + 17y/ x+ y = 23

27x + 17y = 23x + 23y

4x = 6y

x = 3 .
y = 2