A 270 metres long train running at the speed of 120 kmph crosses another train running in opposite direction at the speed of 80 kmph in 9 seconds. What is the length of the other train?

230 m

240 m

260 m

320 m

Explanation:

Relative speed = (120 + 80) km/hr

=$ \left(200 \times\dfrac{5}{18} \right) $m/sec

=$ \left(\dfrac{500}{9} \right) $m/sec.

Let the length of the other train be $ x $ metres.

Then,$ \dfrac{x + 270}{9} $=$ \dfrac{500}{9} $

$\Rightarrow x $ + 270 = 500

$\Rightarrow x $ = 230.