Question

A 270 m long train running at the speed of 120kmph crosses another train running in opposite direction at the speed of 80kmph in 9sec. what is the length of the other train?

Answer 1

Relative speed = (120 + 80) km/hr
   =200 x(5/18)m/sec
   =500/9    m/sec.

Let the length of the other train be x metres.
Then,(x + 270)/9=500/9

 x + 270 = 500
 x = 230.