Discussion Forum

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 ?

Answer:

Explanation:

Relative speed $=(120+80)$ km/hr $=\left(200\times\frac{5}{18}\right)$ m/sec $=\left(\frac{500}{9}\right)$ m/sec.

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

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

$\Leftrightarrow x+270$ $=500$

$\Leftrightarrow x=230$.