Question

Two trains are running in opposite directions with the same speed. If the length of each train is 120 metres and they cross each other in 12 seconds, then the speed of each train (in km/hr) is

• A. 10
• B. 18
• C. 36
• D. 72

Answer 1

The correct option is C 36

Let the speed of each train be $x$ $m/sec$
Then, relative speed of the two trains $=2x$ $m/sec$

Total distance covered$=120+120=240m$

Total time $=12sec$

So $2x=\frac{240}{12}=20$
$2x=20$

$x=10$

$\therefore$ Speed of each train$=10m/sec=10\times \frac{18}{5}=36km/hr$