Two men start together to walk to a certain destination, one at 3 kmph and another at 3.75 kmph. The latter arrives half an hour before the former. The distance is :

Solution (By Examveda Team)

Let the distance be x km
Then,
$$\eqalign{ & \Leftrightarrow \frac{x}{3} - \frac{x}{{3.75}} = \frac{1}{2} \cr & \Leftrightarrow 2.5x - 2x = 3.75 \cr & \Leftrightarrow x = \frac{{3.75}}{{0.50}} \cr & \Leftrightarrow x = \frac{{15}}{2} \cr & \Leftrightarrow x = 7.5{\text{ km}} \cr} $$