P and Q are 27 km away. Two trains with speed of 24 km/hr and 18 km/hr respectively start simultaneously from P and Q and travel in the same direction. They meet at a point R beyond Q. Distance QR is

Solution (By Examveda Team)

Relative speed = 24 - 18 = 6 km/hr
Time required by faster train to overtake slower train $$ = \frac{{27}}{6} = 4\frac{1}{2}{\text{ hr}}$$
$$\therefore $$ Distance between Q and R $$ = 18 \times 4\frac{1}{2} = 81{\text{ km}}$$