Question

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?

• A. 230 m
• B. 240 m
• C. 260 m
• D. 320 m
• E. 340 m

Answer 1

The correct option is A

230 m

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

Let the length of the other train be `x' metres.

Then, $\frac{x+270}{9}=\frac{500}{9}\iff x+270=500\iff x=230.$