Question

A man sees a train passing over a bridge $1$ km long. The length of the train is half that of the bridge. If the train clears the bridge in $2$ min, then the speed of the train is:

• A. $30$ km/hr
• B. $45$ km/hr
• C. $50$ km/hr
• D. $60$ km/hr

Answer 1

The correct option is B $45$ km/hr

Distance travel in 2 minute$=(1+\frac{1}{2})km.=\frac{3}{2}km.$

Distance covered in 1 hour$=(\frac{3}{2}\times \frac{60}{2})km=45km$

$\therefore$ Speed of the train$=45$ km/hr